~aleteoryx/muditaos

5ad878c6c49357da4494e7809b9a026ad662fb85 — Paweł Joński 4 years ago b7e710e
[BH-371] Replace gsl with mainline submodule and move to third-party

Replacing loose gsl files with gsl mainline project as submodule
and moving it to third-party
48 files changed, 81 insertions(+), 4787 deletions(-)

M .gitmodules
M module-apps/CMakeLists.txt
M module-apps/application-calculator/data/CalculatorInputProcessorText.cpp
M module-apps/application-calllog/windows/CallLogDetailsWindow.cpp
M module-apps/application-desktop/models/ActiveNotificationsModel.cpp
M module-apps/application-onboarding/model/EULARepository.cpp
M module-apps/application-settings-new/models/SARInfoRepository.cpp
M module-apps/locks/handlers/LockPolicyHandler.cpp
M module-apps/notifications/NotificationData.cpp
M module-cellular/CMakeLists.txt
M module-cellular/modem/mux/CellularMux.cpp
M module-db/CMakeLists.txt
M module-db/Database/Database.cpp
M module-db/Interface/NotificationsRecord.cpp
M module-gui/CMakeLists.txt
M module-gui/gui/input/InputEvent.cpp
M module-gui/gui/input/InputEvent.hpp
M module-gui/gui/input/Profile.cpp
M module-services/CMakeLists.txt
M module-services/service-cellular/CMakeLists.txt
M module-services/service-cellular/ServiceCellular.cpp
M module-services/service-db/test/test-settings/Database.cpp
M module-services/service-desktop/CMakeLists.txt
M module-services/service-desktop/endpoints/backup/BackupRestore.cpp
M module-services/service-eink/CMakeLists.txt
M module-services/service-eink/EinkDisplay.cpp
M module-services/service-eink/ServiceEink.cpp
M module-services/service-evtmgr/CMakeLists.txt
M module-services/service-evtmgr/screen-light-control/ScreenLightControl.cpp
A module-services/service-evtmgr/screen-light-control/ScreenLightControlParameters.cpp
M module-services/service-evtmgr/screen-light-control/ScreenLightControlParameters.hpp
M module-services/service-gui/ServiceGUI.cpp
M module-utils/CMakeLists.txt
M module-utils/board/cross/log_rt1051.cpp
M module-utils/bootconfig/CMakeLists.txt
M module-utils/bootconfig/src/bootconfig.cpp
D module-utils/gsl/gsl
D module-utils/gsl/gsl_algorithm
D module-utils/gsl/gsl_assert
D module-utils/gsl/gsl_byte
D module-utils/gsl/gsl_util
D module-utils/gsl/multi_span
D module-utils/gsl/pointers
D module-utils/gsl/span
D module-utils/gsl/string_span
M module-utils/log/Logger.cpp
M third-party/CMakeLists.txt
A third-party/gsl
M .gitmodules => .gitmodules +3 -0
@@ 84,3 84,6 @@
[submodule "third-party/littlefs/src"]
	path = third-party/littlefs/src
	url = https://github.com/littlefs-project/littlefs.git
[submodule "third-party/gsl"]
	path = third-party/gsl
	url = https://github.com/microsoft/GSL.git

M module-apps/CMakeLists.txt => module-apps/CMakeLists.txt +1 -0
@@ 125,6 125,7 @@ target_link_libraries(${PROJECT_NAME}
        service-cellular
        service-db
        service-evtmgr
        Microsoft.GSL::GSL
    PUBLIC
        module-audio
        module-bsp

M module-apps/application-calculator/data/CalculatorInputProcessorText.cpp => module-apps/application-calculator/data/CalculatorInputProcessorText.cpp +1 -1
@@ 7,7 7,7 @@
#include <gui/input/InputEvent.hpp>
#include <gui/widgets/Text.hpp>
#include <i18n/i18n.hpp>
#include <module-utils/gsl/gsl_assert>
#include <gsl/assert>

calc::InputProcessorText::InputProcessorText(gsl::strict_not_null<gui::Text *> inputField) : inputField{inputField}
{}

M module-apps/application-calllog/windows/CallLogDetailsWindow.cpp => module-apps/application-calllog/windows/CallLogDetailsWindow.cpp +1 -0
@@ 15,6 15,7 @@
#include <widgets/TextWithIconsWidget.hpp>
#include <widgets/ActiveIconFactory.hpp>

#include <gsl/assert>
#include <i18n/i18n.hpp>
#include <time/time_conversion.hpp>
#include <Style.hpp>

M module-apps/application-desktop/models/ActiveNotificationsModel.cpp => module-apps/application-desktop/models/ActiveNotificationsModel.cpp +2 -0
@@ 11,6 11,8 @@
#include <application-messages/Constants.hpp>
#include <service-appmgr/messages/SwitchRequest.hpp>

#include <gsl/assert>

using namespace gui;

namespace

M module-apps/application-onboarding/model/EULARepository.cpp => module-apps/application-onboarding/model/EULARepository.cpp +1 -1
@@ 1,7 1,7 @@
// Copyright (c) 2017-2021, Mudita Sp. z.o.o. All rights reserved.
// For licensing, see https://github.com/mudita/MuditaOS/LICENSE.md

#include <module-utils/gsl/gsl_util>
#include <gsl/util>
#include "module-utils/i18n/i18n.hpp"

#include "EULARepository.hpp"

M module-apps/application-settings-new/models/SARInfoRepository.cpp => module-apps/application-settings-new/models/SARInfoRepository.cpp +1 -1
@@ 3,7 3,7 @@

#include "SARInfoRepository.hpp"

#include <gsl_util>
#include <gsl/util>
#include <i18n/i18n.hpp>

#include <fstream>

M module-apps/locks/handlers/LockPolicyHandler.cpp => module-apps/locks/handlers/LockPolicyHandler.cpp +1 -1
@@ 4,7 4,7 @@
#include "LockPolicyHandler.hpp"
#include <log/log.hpp>
#include <Application.hpp>
#include <gsl_assert>
#include <gsl/assert>

using namespace locks;


M module-apps/notifications/NotificationData.cpp => module-apps/notifications/NotificationData.cpp +1 -1
@@ 2,7 2,7 @@
// For licensing, see https://github.com/mudita/MuditaOS/LICENSE.md

#include "NotificationData.hpp"
#include <gsl_assert>
#include <gsl/assert>
uint32_t notifications::Notification::priorityPool = 0;

using namespace notifications;

M module-cellular/CMakeLists.txt => module-cellular/CMakeLists.txt +3 -0
@@ 77,6 77,7 @@ target_include_directories(${PROJECT_NAME}
)

target_link_libraries(${PROJECT_NAME}
    PUBLIC
    service-cellular
    service-eink
    service-fota


@@ 87,6 88,8 @@ target_link_libraries(${PROJECT_NAME}
    module-db
    module-bsp
    date::date
    PRIVATE
    Microsoft.GSL::GSL
)

if (${ENABLE_TESTS})

M module-cellular/modem/mux/CellularMux.cpp => module-cellular/modem/mux/CellularMux.cpp +1 -1
@@ 17,7 17,7 @@
#include <SystemManager/messages/DeviceRegistrationMessage.hpp>
#include <time/time_conversion.hpp>

#include <gsl/gsl_util>
#include <gsl/util>

#include <memory>
#include <sstream>

M module-db/CMakeLists.txt => module-db/CMakeLists.txt +8 -1
@@ 176,7 176,14 @@ target_compile_options(${PROJECT_NAME}
    -Wno-error=return-local-addr
)

target_link_libraries(${PROJECT_NAME} module-utils module-vfs )
target_link_libraries(${PROJECT_NAME}
    PUBLIC
    module-utils
    module-vfs

    PRIVATE
    Microsoft.GSL::GSL
)

# Host target configuration(mainly used for unit testing)
if (${ENABLE_TESTS})

M module-db/Database/Database.cpp => module-db/Database/Database.cpp +1 -1
@@ 7,7 7,7 @@
#include "log/log.hpp"

#include <purefs/filesystem_paths.hpp>
#include <gsl/gsl_util>
#include <gsl/util>

#include <cassert>
#include <cstring>

M module-db/Interface/NotificationsRecord.cpp => module-db/Interface/NotificationsRecord.cpp +1 -1
@@ 14,7 14,7 @@

#include <cassert>
#include <vector>
#include <gsl_assert>
#include <gsl/assert>

NotificationsRecord::NotificationsRecord(const NotificationsTableRow &tableRow, std::optional<ContactRecord> record)
    : Record{tableRow.ID}, value{tableRow.value}, contactRecord{std::move(record)}

M module-gui/CMakeLists.txt => module-gui/CMakeLists.txt +1 -0
@@ 27,6 27,7 @@ target_link_libraries(${PROJECT_NAME}
        ${TARGET_LIBRARIES} 
    PRIVATE
        pugixml::pugixml
        Microsoft.GSL::GSL
)

# Board specific compilation definitions,options,include directories and features

M module-gui/gui/input/InputEvent.cpp => module-gui/gui/input/InputEvent.cpp +8 -0
@@ 2,6 2,8 @@
// For licensing, see https://github.com/mudita/MuditaOS/LICENSE.md

#include "InputEvent.hpp"
#include <gsl/assert>

namespace gui
{



@@ 17,4 19,10 @@ namespace gui
        return ss.str();
    }

    auto InputEvent::numericValue() const -> int
    {
        Expects(isDigit());
        return toNumeric(keyCode);
    }

}; // namespace gui

M module-gui/gui/input/InputEvent.hpp => module-gui/gui/input/InputEvent.hpp +2 -7
@@ 6,7 6,6 @@
#include <sstream>
#include <cstdint>
#include <type_traits>
#include <gsl_assert>
#include "bsp/keyboard/key_codes.hpp"
#include "common_data/RawKey.hpp"



@@ 168,14 167,10 @@ namespace gui
            return toNumeric(keyCode) != InvalidNumericKeyCode;
        }

        [[nodiscard]] auto numericValue() const -> int
        {
            Expects(isDigit());
            return toNumeric(keyCode);
        }

        [[nodiscard]] auto str() const -> std::string;

        [[nodiscard]] auto numericValue() const -> int;

      private:
        RawKey rawKey   = {};                     /// RawKey data
        State state     = State::keyPressed;      /// initial translated key state

M module-gui/gui/input/Profile.cpp => module-gui/gui/input/Profile.cpp +1 -1
@@ 5,7 5,7 @@
#include "utf8/UTF8.hpp"
#include "Profile.hpp"
#include <Utils.hpp>
#include <gsl>
#include <gsl/gsl>

namespace gui
{

M module-services/CMakeLists.txt => module-services/CMakeLists.txt +3 -2
@@ 47,8 47,9 @@ target_link_libraries(${PROJECT_NAME} PUBLIC
    module-cellular
    module-audio
    service-fileindexer
        service-antenna
    ${TARGET_LIBRARIES} )
    service-antenna
    ${TARGET_LIBRARIES}
)

# Board specific compilation definitions,options,include directories and features
target_compile_definitions(${PROJECT_NAME} PUBLIC ${PROJECT_CONFIG_DEFINITIONS})

M module-services/service-cellular/CMakeLists.txt => module-services/service-cellular/CMakeLists.txt +1 -0
@@ 52,6 52,7 @@ target_link_libraries(${PROJECT_NAME}
        service-evtmgr
        module-bsp
        module-cellular
        Microsoft.GSL::GSL
    )

if (${ENABLE_TESTS})

M module-services/service-cellular/ServiceCellular.cpp => module-services/service-cellular/ServiceCellular.cpp +1 -1
@@ 92,7 92,7 @@
#include <vector>
#include "checkSmsCenter.hpp"
#include <service-desktop/Constants.hpp>
#include <gsl/gsl_util>
#include <gsl/util>
#include <ticks.hpp>

#include "ServiceCellularPriv.hpp"

M module-services/service-db/test/test-settings/Database.cpp => module-services/service-db/test/test-settings/Database.cpp +1 -1
@@ 6,7 6,7 @@
#include "log/log.hpp"

#include <purefs/filesystem_paths.hpp>
#include <gsl/gsl_util>
#include <gsl/util>

#include <cassert>
#include <cstring>

M module-services/service-desktop/CMakeLists.txt => module-services/service-desktop/CMakeLists.txt +1 -0
@@ 61,6 61,7 @@ target_link_libraries(${PROJECT_NAME}
        crc32
        microtar
        utils-bootconfig
        Microsoft.GSL::GSL
)

if (${ENABLE_TESTS})

M module-services/service-desktop/endpoints/backup/BackupRestore.cpp => module-services/service-desktop/endpoints/backup/BackupRestore.cpp +1 -1
@@ 18,7 18,7 @@
#include <string>
#include <vector>
#include <sys/statvfs.h>
#include <gsl>
#include <gsl/gsl>

namespace sys
{

M module-services/service-eink/CMakeLists.txt => module-services/service-eink/CMakeLists.txt +1 -0
@@ 24,6 24,7 @@ add_library(${PROJECT_NAME} STATIC ${SOURCES})
target_link_libraries( ${PROJECT_NAME}
    module-utils
    service-gui
    Microsoft.GSL::GSL
)

target_include_directories(${PROJECT_NAME}

M module-services/service-eink/EinkDisplay.cpp => module-services/service-eink/EinkDisplay.cpp +1 -1
@@ 4,7 4,7 @@
#include "EinkDisplay.hpp"

#include <gui/core/Color.hpp>
#include <gsl/gsl_util>
#include <gsl/util>
#include <bsp/BoardDefinitions.hpp>
#include <cstdio>
#include <cstring>

M module-services/service-eink/ServiceEink.cpp => module-services/service-eink/ServiceEink.cpp +1 -1
@@ 18,7 18,7 @@

#include <cstring>
#include <memory>
#include <gsl_util>
#include <gsl/util>

namespace service::eink
{

M module-services/service-evtmgr/CMakeLists.txt => module-services/service-evtmgr/CMakeLists.txt +2 -0
@@ 11,6 11,7 @@ set(SOURCES
        battery-brownout-detector/BatteryBrownoutDetector.cpp
        screen-light-control/ControlFunctions.cpp
        screen-light-control/ScreenLightControl.cpp
        screen-light-control/ScreenLightControlParameters.cpp
        vibra/Vibra.cpp
)



@@ 33,6 34,7 @@ target_link_libraries(${PROJECT_NAME}
        service-cellular
        service-desktop
        sml::sml
        Microsoft.GSL::GSL
)

if (${ENABLE_TESTS})

M module-services/service-evtmgr/screen-light-control/ScreenLightControl.cpp => module-services/service-evtmgr/screen-light-control/ScreenLightControl.cpp +1 -0
@@ 2,6 2,7 @@
// For licensing, see https://github.com/mudita/MuditaOS/LICENSE.md

#include "ScreenLightControl.hpp"
#include "ScreenLightControlParameters.hpp"
#include <module-sys/Timers/TimerFactory.hpp>
#include <Service/Service.hpp>


A module-services/service-evtmgr/screen-light-control/ScreenLightControlParameters.cpp => module-services/service-evtmgr/screen-light-control/ScreenLightControlParameters.cpp +21 -0
@@ 0,0 1,21 @@
// Copyright (c) 2017-2021, Mudita Sp. z.o.o. All rights reserved.
// For licensing, see https://github.com/mudita/MuditaOS/LICENSE.md

#include "ScreenLightControlParameters.hpp"

#include <gsl/assert>

namespace screen_light_control
{
    auto Parameters::getAutoModeParams() const noexcept -> const AutomaticModeParameters &
    {
        Expects(hasAutoModeParams());
        return autoModeParams.value();
    }

    auto Parameters::getManualModeParams() const noexcept -> ManualModeParameters
    {
        Expects(hasManualModeParams());
        return manualModeParams.value();
    }
} // namespace screen_light_control

M module-services/service-evtmgr/screen-light-control/ScreenLightControlParameters.hpp => module-services/service-evtmgr/screen-light-control/ScreenLightControlParameters.hpp +2 -11
@@ 4,7 4,6 @@
#pragma once

#include "ControlFunctions.hpp"
#include <gsl_assert>
#include <optional>

namespace screen_light_control


@@ 67,21 66,13 @@ namespace screen_light_control
            return manualModeParams.has_value();
        }

        [[nodiscard]] auto getManualModeParams() const noexcept -> ManualModeParameters
        {
            Expects(hasManualModeParams());
            return manualModeParams.value();
        }
        [[nodiscard]] auto getManualModeParams() const noexcept -> ManualModeParameters;

        [[nodiscard]] bool hasAutoModeParams() const noexcept
        {
            return autoModeParams.has_value();
        }

        [[nodiscard]] auto getAutoModeParams() const noexcept -> const AutomaticModeParameters &
        {
            Expects(hasAutoModeParams());
            return autoModeParams.value();
        }
        [[nodiscard]] auto getAutoModeParams() const noexcept -> const AutomaticModeParameters &;
    };
} // namespace screen_light_control

M module-services/service-gui/ServiceGUI.cpp => module-services/service-gui/ServiceGUI.cpp +1 -1
@@ 20,7 20,7 @@
#include <Timers/TimerFactory.hpp>
#include <SystemManager/SystemManager.hpp>

#include <gsl/gsl_util>
#include <gsl/util>
#include <purefs/filesystem_paths.hpp>

namespace service::gui

M module-utils/CMakeLists.txt => module-utils/CMakeLists.txt +0 -1
@@ 81,7 81,6 @@ target_include_directories(${PROJECT_NAME}
        PUBLIC

        ${CMAKE_CURRENT_SOURCE_DIR}
        ${CMAKE_CURRENT_SOURCE_DIR}/gsl
)

if((${PROJECT_TARGET} STREQUAL "TARGET_RT1051") AND (${SYSTEM_VIEW_ENABLED}))

M module-utils/board/cross/log_rt1051.cpp => module-utils/board/cross/log_rt1051.cpp +0 -1
@@ 3,7 3,6 @@

#include <board.h>
#include <critical.hpp>
#include <gsl/gsl_util>
#include <macros.h>
#include "log/log.hpp"
#include "log/Logger.hpp"

M module-utils/bootconfig/CMakeLists.txt => module-utils/bootconfig/CMakeLists.txt +1 -0
@@ 21,4 21,5 @@ target_link_libraries( ${PROJECT_NAME}
      module-utils
      module-vfs
      crc32
      Microsoft.GSL::GSL
)

M module-utils/bootconfig/src/bootconfig.cpp => module-utils/bootconfig/src/bootconfig.cpp +1 -1
@@ 3,7 3,7 @@
#include <boot/bootconfig.hpp>
#include <boot/bootconstants.hpp>

#include <module-utils/gsl/gsl_util>
#include <gsl/util>
#include <limits.h>
#include <purefs/filesystem_paths.hpp>
#include <source/version.hpp>

D module-utils/gsl/gsl => module-utils/gsl/gsl +0 -29
@@ 1,29 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_GSL_H
#define GSL_GSL_H

#include <gsl/gsl_algorithm> // copy
#include <gsl/gsl_assert>    // Ensures/Expects
#include <gsl/gsl_byte>      // byte
#include <gsl/gsl_util>      // finally()/narrow()/narrow_cast()...
#include <gsl/multi_span>    // multi_span, strided_span...
#include <gsl/pointers>      // owner, not_null
#include <gsl/span>          // span
#include <gsl/string_span>   // zstring, string_span, zstring_builder...

#endif // GSL_GSL_H

D module-utils/gsl/gsl_algorithm => module-utils/gsl/gsl_algorithm +0 -61
@@ 1,61 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_ALGORITHM_H
#define GSL_ALGORITHM_H

#include <gsl/gsl_assert> // for Expects
#include <gsl/span>       // for dynamic_extent, span

#include <algorithm>   // for copy_n
#include <cstddef>     // for ptrdiff_t
#include <type_traits> // for is_assignable

#ifdef _MSC_VER
#pragma warning(push)

// turn off some warnings that are noisy about our Expects statements
#pragma warning(disable : 4127) // conditional expression is constant
#pragma warning(disable : 4996) // unsafe use of std::copy_n

#endif // _MSC_VER

namespace gsl
{
// Note: this will generate faster code than std::copy using span iterator in older msvc+stl
// not necessary for msvc since VS2017 15.8 (_MSC_VER >= 1915)
template <class SrcElementType, std::ptrdiff_t SrcExtent, class DestElementType,
          std::ptrdiff_t DestExtent>
void copy(span<SrcElementType, SrcExtent> src, span<DestElementType, DestExtent> dest)
{
    static_assert(std::is_assignable<decltype(*dest.data()), decltype(*src.data())>::value,
                  "Elements of source span can not be assigned to elements of destination span");
    static_assert(SrcExtent == dynamic_extent || DestExtent == dynamic_extent ||
                      (SrcExtent <= DestExtent),
                  "Source range is longer than target range");

    Expects(dest.size() >= src.size());
    GSL_SUPPRESS(stl.1) // NO-FORMAT: attribute
    std::copy_n(src.data(), src.size(), dest.data());
}

} // namespace gsl

#ifdef _MSC_VER
#pragma warning(pop)
#endif // _MSC_VER

#endif // GSL_ALGORITHM_H

D module-utils/gsl/gsl_assert => module-utils/gsl/gsl_assert +0 -177
@@ 1,177 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_CONTRACTS_H
#define GSL_CONTRACTS_H

#include <exception>
#include <stdexcept> // for logic_error

//
// make suppress attributes parse for some compilers
// Hopefully temporary until suppression standardization occurs
//
#if defined(__clang__)
#define GSL_SUPPRESS(x) [[gsl::suppress("x")]]
#else
#if defined(_MSC_VER)
#define GSL_SUPPRESS(x) [[gsl::suppress(x)]]
#else
#define GSL_SUPPRESS(x)
#endif // _MSC_VER
#endif // __clang__

//
// Temporary until MSVC STL supports no-exceptions mode.
// Currently terminate is a no-op in this mode, so we add termination behavior back
//
#if defined(_MSC_VER) && defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS
#define GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND
#include <intrin.h>
#define RANGE_CHECKS_FAILURE 0

#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Winvalid-noreturn"
#endif

#endif

//
// There are three configuration options for this GSL implementation's behavior
// when pre/post conditions on the GSL types are violated:
//
// 1. GSL_TERMINATE_ON_CONTRACT_VIOLATION: std::terminate will be called (default)
// 2. GSL_THROW_ON_CONTRACT_VIOLATION: a gsl::fail_fast exception will be thrown
// 3. GSL_UNENFORCED_ON_CONTRACT_VIOLATION: nothing happens
//
#if !(defined(GSL_THROW_ON_CONTRACT_VIOLATION) || defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) ||  \
      defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION))
#define GSL_TERMINATE_ON_CONTRACT_VIOLATION
#endif

#define GSL_STRINGIFY_DETAIL(x) #x
#define GSL_STRINGIFY(x) GSL_STRINGIFY_DETAIL(x)

#if defined(__clang__) || defined(__GNUC__)
#define GSL_LIKELY(x) __builtin_expect(!!(x), 1)
#define GSL_UNLIKELY(x) __builtin_expect(!!(x), 0)
#else
#define GSL_LIKELY(x) (!!(x))
#define GSL_UNLIKELY(x) (!!(x))
#endif

//
// GSL_ASSUME(cond)
//
// Tell the optimizer that the predicate cond must hold. It is unspecified
// whether or not cond is actually evaluated.
//
#ifdef _MSC_VER
#define GSL_ASSUME(cond) __assume(cond)
#elif defined(__GNUC__)
#define GSL_ASSUME(cond) ((cond) ? static_cast<void>(0) : __builtin_unreachable())
#else
#define GSL_ASSUME(cond) static_cast<void>((cond) ? 0 : 0)
#endif

//
// GSL.assert: assertions
//

namespace gsl
{
struct fail_fast : public std::logic_error
{
    explicit fail_fast(char const* const message) : std::logic_error(message) {}
};

namespace details
{
#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND)

    typedef void  (__cdecl *terminate_handler)();

    GSL_SUPPRESS(f.6) // NO-FORMAT: attribute
    [[noreturn]] inline void __cdecl default_terminate_handler()
    {
        __fastfail(RANGE_CHECKS_FAILURE);
    }

    inline gsl::details::terminate_handler& get_terminate_handler() noexcept
    {
        static terminate_handler handler = &default_terminate_handler;
        return handler;
    }

#endif

    [[noreturn]] inline void terminate() noexcept
    {
#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND)
        (*gsl::details::get_terminate_handler())();
#else
        std::terminate();
#endif
    }

#if defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION)

    template <typename Exception>
    [[noreturn]] void throw_exception(Exception&&) noexcept
    {
        gsl::details::terminate();
    }

#else

    template <typename Exception>
    [[noreturn]] void throw_exception(Exception&& exception)
    {
        throw std::forward<Exception>(exception);
    }

#endif // GSL_TERMINATE_ON_CONTRACT_VIOLATION

} // namespace details
} // namespace gsl

#if defined(GSL_THROW_ON_CONTRACT_VIOLATION)

#define GSL_CONTRACT_CHECK(type, cond)                                                             \
    (GSL_LIKELY(cond) ? static_cast<void>(0)                                                       \
                      : gsl::details::throw_exception(gsl::fail_fast(                              \
                            "GSL: " type " failure at " __FILE__ ": " GSL_STRINGIFY(__LINE__))))

#elif defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION)

#define GSL_CONTRACT_CHECK(type, cond)                                                             \
    (GSL_LIKELY(cond) ? static_cast<void>(0) : gsl::details::terminate())

#elif defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION)

#define GSL_CONTRACT_CHECK(type, cond) GSL_ASSUME(cond)

#endif // GSL_THROW_ON_CONTRACT_VIOLATION

#define Expects(cond) GSL_CONTRACT_CHECK("Precondition", cond)
#define Ensures(cond) GSL_CONTRACT_CHECK("Postcondition", cond)

#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND) && defined(__clang__)
#pragma clang diagnostic pop
#endif

#endif // GSL_CONTRACTS_H

D module-utils/gsl/gsl_byte => module-utils/gsl/gsl_byte +0 -203
@@ 1,203 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_BYTE_H
#define GSL_BYTE_H

//
// make suppress attributes work for some compilers
// Hopefully temporary until suppression standardization occurs
//
#if defined(__clang__)
#define GSL_SUPPRESS(x) [[gsl::suppress("x")]]
#else
#if defined(_MSC_VER)
#define GSL_SUPPRESS(x) [[gsl::suppress(x)]]
#else
#define GSL_SUPPRESS(x)
#endif // _MSC_VER
#endif // __clang__

#include <type_traits>

#ifdef _MSC_VER

#pragma warning(push)

// Turn MSVC /analyze rules that generate too much noise. TODO: fix in the tool.
#pragma warning(disable : 26493) // don't use c-style casts // TODO: MSVC suppression in templates does not always work

#ifndef GSL_USE_STD_BYTE
// this tests if we are under MSVC and the standard lib has std::byte and it is enabled
#if defined(_HAS_STD_BYTE) && _HAS_STD_BYTE

#define GSL_USE_STD_BYTE 1

#else // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE

#define GSL_USE_STD_BYTE 0

#endif // defined(_HAS_STD_BYTE) && _HAS_STD_BYTE
#endif // GSL_USE_STD_BYTE

#else // _MSC_VER

#ifndef GSL_USE_STD_BYTE
// this tests if we are under GCC or Clang with enough -std:c++1z power to get us std::byte
// also check if libc++ version is sufficient (> 5.0) or libstc++ actually contains std::byte
#if defined(__cplusplus) && (__cplusplus >= 201703L) && \
  (defined(__cpp_lib_byte) && (__cpp_lib_byte >= 201603)  || \
   defined(_LIBCPP_VERSION) && (_LIBCPP_VERSION >= 5000))

#define GSL_USE_STD_BYTE 1
#include <cstddef>

#else // defined(__cplusplus) && (__cplusplus >= 201703L) &&
      //   (defined(__cpp_lib_byte) && (__cpp_lib_byte >= 201603)  ||
      //    defined(_LIBCPP_VERSION) && (_LIBCPP_VERSION >= 5000))

#define GSL_USE_STD_BYTE 0

#endif //defined(__cplusplus) && (__cplusplus >= 201703L) &&
       //   (defined(__cpp_lib_byte) && (__cpp_lib_byte >= 201603)  ||
       //    defined(_LIBCPP_VERSION) && (_LIBCPP_VERSION >= 5000))
#endif // GSL_USE_STD_BYTE

#endif // _MSC_VER

// Use __may_alias__ attribute on gcc and clang
#if defined __clang__ || (defined(__GNUC__) && __GNUC__ > 5)
#define byte_may_alias __attribute__((__may_alias__))
#else // defined __clang__ || defined __GNUC__
#define byte_may_alias
#endif // defined __clang__ || defined __GNUC__

namespace gsl
{
#if GSL_USE_STD_BYTE

using std::byte;
using std::to_integer;

#else // GSL_USE_STD_BYTE

// This is a simple definition for now that allows
// use of byte within span<> to be standards-compliant
enum class byte_may_alias byte : unsigned char
{
};

template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
constexpr byte& operator<<=(byte& b, IntegerType shift) noexcept
{
    return b = byte(static_cast<unsigned char>(b) << shift);
}

template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
constexpr byte operator<<(byte b, IntegerType shift) noexcept
{
    return byte(static_cast<unsigned char>(b) << shift);
}

template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
constexpr byte& operator>>=(byte& b, IntegerType shift) noexcept
{
    return b = byte(static_cast<unsigned char>(b) >> shift);
}

template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
constexpr byte operator>>(byte b, IntegerType shift) noexcept
{
    return byte(static_cast<unsigned char>(b) >> shift);
}

constexpr byte& operator|=(byte& l, byte r) noexcept
{
    return l = byte(static_cast<unsigned char>(l) | static_cast<unsigned char>(r));
}

constexpr byte operator|(byte l, byte r) noexcept
{
    return byte(static_cast<unsigned char>(l) | static_cast<unsigned char>(r));
}

constexpr byte& operator&=(byte& l, byte r) noexcept
{
    return l = byte(static_cast<unsigned char>(l) & static_cast<unsigned char>(r));
}

constexpr byte operator&(byte l, byte r) noexcept
{
    return byte(static_cast<unsigned char>(l) & static_cast<unsigned char>(r));
}

constexpr byte& operator^=(byte& l, byte r) noexcept
{
    return l = byte(static_cast<unsigned char>(l) ^ static_cast<unsigned char>(r));
}

constexpr byte operator^(byte l, byte r) noexcept
{
    return byte(static_cast<unsigned char>(l) ^ static_cast<unsigned char>(r));
}

constexpr byte operator~(byte b) noexcept { return byte(~static_cast<unsigned char>(b)); }

template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
constexpr IntegerType to_integer(byte b) noexcept
{
    return static_cast<IntegerType>(b);
}

#endif // GSL_USE_STD_BYTE

template <bool E, typename T>
constexpr byte to_byte_impl(T t) noexcept
{
    static_assert(
        E, "gsl::to_byte(t) must be provided an unsigned char, otherwise data loss may occur. "
           "If you are calling to_byte with an integer contant use: gsl::to_byte<t>() version.");
    return static_cast<byte>(t);
}
template <>
// NOTE: need suppression since c++14 does not allow "return {t}"
// GSL_SUPPRESS(type.4) // NO-FORMAT: attribute // TODO: suppression does not work
constexpr byte to_byte_impl<true, unsigned char>(unsigned char t) noexcept
{
    return byte(t);
}

template <typename T>
constexpr byte to_byte(T t) noexcept
{
    return to_byte_impl<std::is_same<T, unsigned char>::value, T>(t);
}

template <int I>
constexpr byte to_byte() noexcept
{
    static_assert(I >= 0 && I <= 255,
                  "gsl::byte only has 8 bits of storage, values must be in range 0-255");
    return static_cast<byte>(I);
}

} // namespace gsl

#ifdef _MSC_VER
#pragma warning(pop)
#endif // _MSC_VER

#endif // GSL_BYTE_H

D module-utils/gsl/gsl_util => module-utils/gsl/gsl_util +0 -175
@@ 1,175 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_UTIL_H
#define GSL_UTIL_H

#include <gsl/gsl_assert> // for Expects

#include <array>
#include <cstddef>          // for ptrdiff_t, size_t
#include <exception>        // for exception
#include <initializer_list> // for initializer_list
#include <type_traits>      // for is_signed, integral_constant
#include <utility>          // for forward

#if defined(_MSC_VER) && !defined(__clang__)

#pragma warning(push)
#pragma warning(disable : 4127) // conditional expression is constant

#if _MSC_VER < 1910
#pragma push_macro("constexpr")
#define constexpr /*constexpr*/
#endif            // _MSC_VER < 1910
#endif            // _MSC_VER

#if (defined(_MSC_VER) && _MSC_VER < 1910) || (!defined(__clang__) && defined(__GNUC__) && __GUNC__ < 6)
#define GSL_CONSTEXPR_NARROW 0
#else
#define GSL_CONSTEXPR_NARROW 1
#endif

namespace gsl
{
//
// GSL.util: utilities
//

// index type for all container indexes/subscripts/sizes
using index = std::ptrdiff_t;

// final_action allows you to ensure something gets run at the end of a scope
template <class F>
class final_action
{
public:
    explicit final_action(F f) noexcept : f_(std::move(f)) {}

    final_action(final_action&& other) noexcept : f_(std::move(other.f_)), invoke_(other.invoke_)
    {
        other.invoke_ = false;
    }

    final_action(const final_action&) = delete;
    final_action& operator=(const final_action&) = delete;
    final_action& operator=(final_action&&) = delete;

    GSL_SUPPRESS(f.6) // NO-FORMAT: attribute // terminate if throws
    ~final_action() noexcept
    {
        if (invoke_) f_();
    }

private:
    F f_;
    bool invoke_{true};
};

// finally() - convenience function to generate a final_action
template <class F>
final_action<F> finally(const F& f) noexcept
{
    return final_action<F>(f);
}

template <class F>
final_action<F> finally(F&& f) noexcept
{
    return final_action<F>(std::forward<F>(f));
}

// narrow_cast(): a searchable way to do narrowing casts of values
template <class T, class U>
GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
constexpr T narrow_cast(U&& u) noexcept
{
    return static_cast<T>(std::forward<U>(u));
}

struct narrowing_error : public std::exception
{
};

namespace details
{
    template <class T, class U>
    struct is_same_signedness
        : public std::integral_constant<bool, std::is_signed<T>::value == std::is_signed<U>::value>
    {
    };
} // namespace details

// narrow() : a checked version of narrow_cast() that throws if the cast changed the value
template <class T, class U>
GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
GSL_SUPPRESS(f.6) // NO-FORMAT: attribute // TODO: MSVC /analyze does not recognise noexcept(false)
#if GSL_CONSTEXPR_NARROW
constexpr
#endif
T narrow(U u) noexcept(false)
{
    T t = narrow_cast<T>(u);
    if (static_cast<U>(t) != u) gsl::details::throw_exception(narrowing_error());
    if (!details::is_same_signedness<T, U>::value && ((t < T{}) != (u < U{})))
        gsl::details::throw_exception(narrowing_error());
    return t;
}

//
// at() - Bounds-checked way of accessing builtin arrays, std::array, std::vector
//
template <class T, std::size_t N>
GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
constexpr T& at(T (&arr)[N], const index i)
{
    Expects(i >= 0 && i < narrow_cast<index>(N));
    return arr[narrow_cast<std::size_t>(i)];
}

template <class Cont>
GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
constexpr auto at(Cont& cont, const index i) -> decltype(cont[cont.size()])
{
    Expects(i >= 0 && i < narrow_cast<index>(cont.size()));
    using size_type = decltype(cont.size());
    return cont[narrow_cast<size_type>(i)];
}

template <class T>
GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
constexpr T at(const std::initializer_list<T> cont, const index i)
{
    Expects(i >= 0 && i < narrow_cast<index>(cont.size()));
    return *(cont.begin() + i);
}

} // namespace gsl

#if defined(_MSC_VER) && !defined(__clang__)
#if _MSC_VER < 1910
#undef constexpr
#pragma pop_macro("constexpr")

#endif // _MSC_VER < 1910

#pragma warning(pop)

#endif // _MSC_VER

#endif // GSL_UTIL_H

D module-utils/gsl/multi_span => module-utils/gsl/multi_span +0 -2293
@@ 1,2293 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_MULTI_SPAN_H
#define GSL_MULTI_SPAN_H

#include <gsl/gsl_assert> // for Expects
#include <gsl/gsl_byte>   // for byte
#include <gsl/gsl_util>   // for narrow_cast

#include <algorithm> // for transform, lexicographical_compare
#include <array>     // for array
#include <cassert>
#include <cstddef>          // for ptrdiff_t, size_t, nullptr_t
#include <cstdint>          // for PTRDIFF_MAX
#include <functional>       // for divides, multiplies, minus, negate, plus
#include <initializer_list> // for initializer_list
#include <iterator>         // for iterator, random_access_iterator_tag
#include <limits>           // for numeric_limits
#include <new>
#include <numeric>
#include <stdexcept>
#include <string>      // for basic_string
#include <type_traits> // for enable_if_t, remove_cv_t, is_same, is_co...
#include <utility>

#if defined(_MSC_VER) && !defined(__clang__)

// turn off some warnings that are noisy about our Expects statements
#pragma warning(push)
#pragma warning(disable : 4127) // conditional expression is constant
#pragma warning(disable : 4702) // unreachable code

// Turn MSVC /analyze rules that generate too much noise. TODO: fix in the tool.
#pragma warning(disable : 26495) // uninitalized member when constructor calls constructor
#pragma warning(disable : 26473) // in some instantiations we cast to the same type
#pragma warning(disable : 26490) // TODO: bug in parser - attributes and templates
#pragma warning(disable : 26465) // TODO: bug - suppression does not work on template functions

#if _MSC_VER < 1910
#pragma push_macro("constexpr")
#define constexpr /*constexpr*/

#endif                          // _MSC_VER < 1910
#endif                          // _MSC_VER

// GCC 7 does not like the signed unsigned missmatch (size_t ptrdiff_t)
// While there is a conversion from signed to unsigned, it happens at
// compiletime, so the compiler wouldn't have to warn indiscriminently, but
// could check if the source value actually doesn't fit into the target type
// and only warn in those cases.
#if defined(__GNUC__) && __GNUC__ > 6
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsign-conversion"
#endif

namespace gsl
{

/*
** begin definitions of index and bounds
*/
namespace details
{
    template <typename SizeType>
    struct SizeTypeTraits
    {
        static const SizeType max_value = std::numeric_limits<SizeType>::max();
    };

    template <typename... Ts>
    class are_integral : public std::integral_constant<bool, true>
    {
    };

    template <typename T, typename... Ts>
    class are_integral<T, Ts...>
        : public std::integral_constant<bool,
                                        std::is_integral<T>::value && are_integral<Ts...>::value>
    {
    };
} // namespace details

template <std::size_t Rank>
class multi_span_index final
{
    static_assert(Rank > 0, "Rank must be greater than 0!");

    template <std::size_t OtherRank>
    friend class multi_span_index;

public:
    static const std::size_t rank = Rank;
    using value_type = std::ptrdiff_t;
    using size_type = value_type;
    using reference = std::add_lvalue_reference_t<value_type>;
    using const_reference = std::add_lvalue_reference_t<std::add_const_t<value_type>>;

    constexpr multi_span_index() noexcept {}

    constexpr multi_span_index(const value_type (&values)[Rank]) noexcept
    {
        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        GSL_SUPPRESS(bounds.3) // NO-FORMAT: attribute
        std::copy(values, values + Rank, elems);
    }

    template <typename... Ts, typename = std::enable_if_t<(sizeof...(Ts) == Rank) &&
                                                          details::are_integral<Ts...>::value>>
    constexpr multi_span_index(Ts... ds) noexcept : elems{narrow_cast<value_type>(ds)...}
    {}

    constexpr multi_span_index(const multi_span_index& other) noexcept = default;

    constexpr multi_span_index& operator=(const multi_span_index& rhs) noexcept = default;

    // Preconditions: component_idx < rank
    GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr reference operator[](std::size_t component_idx)
    {
        Expects(component_idx < Rank); // Component index must be less than rank
        return elems[component_idx];
    }

    // Preconditions: component_idx < rank
    GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr const_reference operator[](std::size_t component_idx) const 
    {
        Expects(component_idx < Rank); // Component index must be less than rank
        return elems[component_idx];
    }

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    GSL_SUPPRESS(bounds.3) // NO-FORMAT: attribute
    constexpr bool operator==(const multi_span_index& rhs) const
    {
        return std::equal(elems, elems + rank, rhs.elems);
    }

    constexpr bool operator!=(const multi_span_index& rhs) const
    {
        return !(*this == rhs);
    }

    constexpr multi_span_index operator+() const noexcept { return *this; }

    constexpr multi_span_index operator-() const
    {
        multi_span_index ret = *this;
        std::transform(ret, ret + rank, ret, std::negate<value_type>{});
        return ret;
    }

    constexpr multi_span_index operator+(const multi_span_index& rhs) const
    {
        multi_span_index ret = *this;
        ret += rhs;
        return ret;
    }

    constexpr multi_span_index operator-(const multi_span_index& rhs) const
    {
        multi_span_index ret = *this;
        ret -= rhs;
        return ret;
    }

    constexpr multi_span_index& operator+=(const multi_span_index& rhs)
    {
        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        GSL_SUPPRESS(bounds.3) // NO-FORMAT: attribute
        std::transform(elems, elems + rank, rhs.elems, elems,
                       std::plus<value_type>{});
        return *this;
    }

    constexpr multi_span_index& operator-=(const multi_span_index& rhs)
    {
        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        GSL_SUPPRESS(bounds.3) // NO-FORMAT: attribute
        std::transform(elems, elems + rank, rhs.elems, elems, std::minus<value_type>{});
        return *this;
    }

    constexpr multi_span_index operator*(value_type v) const
    {
        multi_span_index ret = *this;
        ret *= v;
        return ret;
    }

    constexpr multi_span_index operator/(value_type v) const
    {
        multi_span_index ret = *this;
        ret /= v;
        return ret;
    }

    friend constexpr multi_span_index operator*(value_type v, const multi_span_index& rhs)
    {
        return rhs * v;
    }

    constexpr multi_span_index& operator*=(value_type v)
    {
        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        GSL_SUPPRESS(bounds.3) // NO-FORMAT: attribute
        std::transform(elems, elems + rank, elems,
                       [v](value_type x) { return std::multiplies<value_type>{}(x, v); });
        return *this;
    }

    constexpr multi_span_index& operator/=(value_type v)
    {
        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        GSL_SUPPRESS(bounds.3) // NO-FORMAT: attribute
        std::transform(elems, elems + rank, elems,
                       [v](value_type x) { return std::divides<value_type>{}(x, v); });
        return *this;
    }

private:
    value_type elems[Rank] = {};
};

#if !defined(_MSC_VER) || _MSC_VER >= 1910

struct static_bounds_dynamic_range_t
{
    template <typename T, typename = std::enable_if_t<std::is_integral<T>::value>>
    constexpr operator T() const noexcept
    {
        return narrow_cast<T>(-1);
    }
};

constexpr bool operator==(static_bounds_dynamic_range_t, static_bounds_dynamic_range_t) noexcept
{
    return true;
}

constexpr bool operator!=(static_bounds_dynamic_range_t, static_bounds_dynamic_range_t) noexcept
{
    return false;
}

template <typename T, typename = std::enable_if_t<std::is_integral<T>::value>>
constexpr bool operator==(static_bounds_dynamic_range_t, T other) noexcept
{
    return narrow_cast<T>(-1) == other;
}

template <typename T, typename = std::enable_if_t<std::is_integral<T>::value>>
constexpr bool operator==(T left, static_bounds_dynamic_range_t right) noexcept
{
    return right == left;
}

template <typename T, typename = std::enable_if_t<std::is_integral<T>::value>>
constexpr bool operator!=(static_bounds_dynamic_range_t, T other) noexcept
{
    return narrow_cast<T>(-1) != other;
}

template <typename T, typename = std::enable_if_t<std::is_integral<T>::value>>
constexpr bool operator!=(T left, static_bounds_dynamic_range_t right) noexcept
{
    return right != left;
}

constexpr static_bounds_dynamic_range_t dynamic_range{};
#else
const std::ptrdiff_t dynamic_range = -1;
#endif

struct generalized_mapping_tag
{
};
struct contiguous_mapping_tag : generalized_mapping_tag
{
};

namespace details
{

    template <std::ptrdiff_t Left, std::ptrdiff_t Right>
    struct LessThan
    {
        static const bool value = Left < Right;
    };

    template <std::ptrdiff_t... Ranges>
    struct BoundsRanges
    {
        using size_type = std::ptrdiff_t;
        static const size_type Depth = 0;
        static const size_type DynamicNum = 0;
        static const size_type CurrentRange = 1;
        static const size_type TotalSize = 1;

        // TODO : following signature is for work around VS bug
        template <typename OtherRange>
        constexpr BoundsRanges(const OtherRange&, bool /* firstLevel */)
        {}

        constexpr BoundsRanges(const std::ptrdiff_t* const) {}
        constexpr BoundsRanges() noexcept = default;

        template <typename T, std::size_t Dim>
        constexpr void serialize(T&) const
        {}

        template <typename T, std::size_t Dim>
        constexpr size_type linearize(const T&) const
        {
            return 0;
        }

        template <typename T, std::size_t Dim>
        constexpr size_type contains(const T&) const
        {
            return -1;
        }

        constexpr size_type elementNum(std::size_t) const noexcept { return 0; }

        constexpr size_type totalSize() const noexcept { return TotalSize; }

        constexpr bool operator==(const BoundsRanges&) const noexcept { return true; }
    };

    template <std::ptrdiff_t... RestRanges>
    struct BoundsRanges<dynamic_range, RestRanges...> : BoundsRanges<RestRanges...>
    {
        using Base = BoundsRanges<RestRanges...>;
        using size_type = std::ptrdiff_t;
        static const std::size_t Depth = Base::Depth + 1;
        static const std::size_t DynamicNum = Base::DynamicNum + 1;
        static const size_type CurrentRange = dynamic_range;
        static const size_type TotalSize = dynamic_range;

    private:
        size_type m_bound;

    public:
        GSL_SUPPRESS(f.23) // NO-FORMAT: attribute // this pointer type is cannot be assigned nullptr - issue in not_null
        GSL_SUPPRESS(bounds.1)  // NO-FORMAT: attribute
        constexpr BoundsRanges(const std::ptrdiff_t* const arr)
            : Base(arr + 1), m_bound(*arr * this->Base::totalSize())
        {
            Expects(0 <= *arr);
        }

        constexpr BoundsRanges() noexcept : m_bound(0) {}

        template <std::ptrdiff_t OtherRange, std::ptrdiff_t... RestOtherRanges>
        constexpr BoundsRanges(const BoundsRanges<OtherRange, RestOtherRanges...>& other,
                     bool /* firstLevel */ = true)
            : Base(static_cast<const BoundsRanges<RestOtherRanges...>&>(other), false)
            , m_bound(other.totalSize())
        {}

        template <typename T, std::size_t Dim = 0>
        constexpr void serialize(T& arr) const
        {
            arr[Dim] = elementNum();
            this->Base::template serialize<T, Dim + 1>(arr);
        }

        template <typename T, std::size_t Dim = 0>
        GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
        constexpr size_type linearize(const T& arr) const
        {
            const size_type index = this->Base::totalSize() * arr[Dim];
            Expects(index < m_bound);
            return index + this->Base::template linearize<T, Dim + 1>(arr);
        }

        template <typename T, std::size_t Dim = 0>
        constexpr size_type contains(const T& arr) const
        {
            const ptrdiff_t last = this->Base::template contains<T, Dim + 1>(arr);
            if (last == -1) return -1;
            const ptrdiff_t cur = this->Base::totalSize() * arr[Dim];
            return cur < m_bound ? cur + last : -1;
        }

        GSL_SUPPRESS(c.128) // NO-FORMAT: attribute // no pointers to BoundsRanges should be ever used
        constexpr size_type totalSize() const noexcept
        {
            return m_bound;
        }

        GSL_SUPPRESS(c.128) // NO-FORMAT: attribute // no pointers to BoundsRanges should be ever used
        constexpr size_type elementNum() const noexcept
        {
            return totalSize() / this->Base::totalSize();
        }

        GSL_SUPPRESS(c.128) // NO-FORMAT: attribute // no pointers to BoundsRanges should be ever used
        constexpr size_type elementNum(std::size_t dim) const noexcept
        {
            if (dim > 0)
                return this->Base::elementNum(dim - 1);
            else
                return elementNum();
        }

        constexpr bool operator==(const BoundsRanges& rhs) const noexcept
        {
            return m_bound == rhs.m_bound &&
                   static_cast<const Base&>(*this) == static_cast<const Base&>(rhs);
        }
    };

    template <std::ptrdiff_t CurRange, std::ptrdiff_t... RestRanges>
    struct BoundsRanges<CurRange, RestRanges...> : BoundsRanges<RestRanges...>
    {
        using Base = BoundsRanges<RestRanges...>;
        using size_type = std::ptrdiff_t;
        static const std::size_t Depth = Base::Depth + 1;
        static const std::size_t DynamicNum = Base::DynamicNum;
        static const size_type CurrentRange = CurRange;
        static const size_type TotalSize =
            Base::TotalSize == dynamic_range ? dynamic_range : CurrentRange * Base::TotalSize;

        constexpr BoundsRanges(const std::ptrdiff_t* const arr) : Base(arr) {}
        constexpr BoundsRanges() = default;

        template <std::ptrdiff_t OtherRange, std::ptrdiff_t... RestOtherRanges>
        constexpr BoundsRanges(const BoundsRanges<OtherRange, RestOtherRanges...>& other,
                     bool firstLevel = true)
            : Base(static_cast<const BoundsRanges<RestOtherRanges...>&>(other), false)
        {
            GSL_SUPPRESS(type.4) // NO-FORMAT: attribute // TODO: false positive
            (void) firstLevel;
        }

        template <typename T, std::size_t Dim = 0>
        constexpr void serialize(T& arr) const
        {
            arr[Dim] = elementNum();
            this->Base::template serialize<T, Dim + 1>(arr);
        }

        template <typename T, std::size_t Dim = 0>
        constexpr size_type linearize(const T& arr) const
        {
            GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
            Expects(arr[Dim] >= 0 && arr[Dim] < CurrentRange); // Index is out of range
            GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
            const ptrdiff_t d = arr[Dim];
            return this->Base::totalSize() * d +
                   this->Base::template linearize<T, Dim + 1>(arr);
        }

        template <typename T, std::size_t Dim = 0>
        constexpr size_type contains(const T& arr) const
        {
            if (arr[Dim] >= CurrentRange) return -1;
            const size_type last = this->Base::template contains<T, Dim + 1>(arr);
            if (last == -1) return -1;
            return this->Base::totalSize() * arr[Dim] + last;
        }

        GSL_SUPPRESS(c.128) // NO-FORMAT: attribute // no pointers to BoundsRanges should be ever used
        constexpr size_type totalSize() const noexcept
        {
            return CurrentRange * this->Base::totalSize();
        }

        GSL_SUPPRESS(c.128) // NO-FORMAT: attribute // no pointers to BoundsRanges should be ever used
        constexpr size_type elementNum() const noexcept
        {
            return CurrentRange;
        }

        GSL_SUPPRESS(c.128) // NO-FORMAT: attribute // no pointers to BoundsRanges should be ever used
        constexpr size_type elementNum(std::size_t dim) const noexcept
        {
            if (dim > 0)
                return this->Base::elementNum(dim - 1);
            else
                return elementNum();
        }

        constexpr bool operator==(const BoundsRanges& rhs) const noexcept
        {
            return static_cast<const Base&>(*this) == static_cast<const Base&>(rhs);
        }
    };

    template <typename SourceType, typename TargetType>
    struct BoundsRangeConvertible
        : public std::integral_constant<bool, (SourceType::TotalSize >= TargetType::TotalSize ||
                                               TargetType::TotalSize == dynamic_range ||
                                               SourceType::TotalSize == dynamic_range ||
                                               TargetType::TotalSize == 0)>
    {
    };

    template <typename TypeChain>
    struct TypeListIndexer
    {
        const TypeChain& obj_;
        constexpr TypeListIndexer(const TypeChain& obj) : obj_(obj) {}

        template <std::size_t N>
        constexpr const TypeChain& getObj(std::true_type)
        {
            return obj_;
        }

        template <std::size_t N, typename MyChain = TypeChain,
                  typename MyBase = typename MyChain::Base>
        constexpr auto getObj(std::false_type)
            -> decltype(TypeListIndexer<MyBase>(static_cast<const MyBase&>(obj_)).template get<N>())
        {
            return TypeListIndexer<MyBase>(static_cast<const MyBase&>(obj_)).template get<N>();
        }

        template <std::size_t N>
        constexpr auto get() -> decltype(getObj<N - 1>(std::integral_constant<bool, N == 0>()))
        {
            return getObj<N - 1>(std::integral_constant<bool, N == 0>());
        }
    };

    template <typename TypeChain>
    constexpr TypeListIndexer<TypeChain> createTypeListIndexer(const TypeChain& obj)
    {
        return TypeListIndexer<TypeChain>(obj);
    }

    template <std::size_t Rank, bool Enabled = (Rank > 1),
              typename Ret = std::enable_if_t<Enabled, multi_span_index<Rank - 1>>>
    constexpr Ret shift_left(const multi_span_index<Rank>& other) noexcept
    {
        Ret ret{};
        for (std::size_t i = 0; i < Rank - 1; ++i)
        {
            GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
                ret[i] = other[i + 1];
        }
        return ret;
    }
} // namespace details

template <typename IndexType>
class bounds_iterator;

template <std::ptrdiff_t... Ranges>
class static_bounds
{
public:
    static_bounds(const details::BoundsRanges<Ranges...>&) {}
};

template <std::ptrdiff_t FirstRange, std::ptrdiff_t... RestRanges>
class static_bounds<FirstRange, RestRanges...>
{
    using MyRanges = details::BoundsRanges<FirstRange, RestRanges...>;

    MyRanges m_ranges;
    constexpr static_bounds(const MyRanges& range) noexcept : m_ranges(range) {}

    template <std::ptrdiff_t... OtherRanges>
    friend class static_bounds;

public:
    static const std::size_t rank = MyRanges::Depth;
    static const std::size_t dynamic_rank = MyRanges::DynamicNum;
    static const std::ptrdiff_t static_size = MyRanges::TotalSize;

    using size_type = std::ptrdiff_t;
    using index_type = multi_span_index<rank>;
    using const_index_type = std::add_const_t<index_type>;
    using iterator = bounds_iterator<const_index_type>;
    using const_iterator = bounds_iterator<const_index_type>;
    using difference_type = std::ptrdiff_t;
    using sliced_type = static_bounds<RestRanges...>;
    using mapping_type = contiguous_mapping_tag;

    constexpr static_bounds() /*noexcept*/ = default;

    template <typename SourceType, typename TargetType, std::size_t Rank>
    struct BoundsRangeConvertible2;

    template <std::size_t Rank, typename SourceType, typename TargetType,
              typename Ret = BoundsRangeConvertible2<typename SourceType::Base,
                                                     typename TargetType::Base, Rank>>
    static auto helpBoundsRangeConvertible(SourceType, TargetType, std::true_type) -> Ret;

    template <std::size_t Rank, typename SourceType, typename TargetType>
    static auto helpBoundsRangeConvertible(SourceType, TargetType, ...) -> std::false_type;

    template <typename SourceType, typename TargetType, std::size_t Rank>
    struct BoundsRangeConvertible2
        : decltype(helpBoundsRangeConvertible<Rank - 1>(
              SourceType(), TargetType(),
              std::integral_constant<bool,
                                     SourceType::Depth == TargetType::Depth &&
                                         (SourceType::CurrentRange == TargetType::CurrentRange ||
                                          TargetType::CurrentRange == dynamic_range ||
                                          SourceType::CurrentRange == dynamic_range)>()))
    {
    };

    template <typename SourceType, typename TargetType>
    struct BoundsRangeConvertible2<SourceType, TargetType, 0> : std::true_type
    {
    };

    template <typename SourceType, typename TargetType, std::ptrdiff_t Rank = TargetType::Depth>
    struct BoundsRangeConvertible
        : decltype(helpBoundsRangeConvertible<Rank - 1>(
              SourceType(), TargetType(),
              std::integral_constant<bool,
                                     SourceType::Depth == TargetType::Depth &&
                                         (!details::LessThan<SourceType::CurrentRange,
                                                             TargetType::CurrentRange>::value ||
                                          TargetType::CurrentRange == dynamic_range ||
                                          SourceType::CurrentRange == dynamic_range)>()))
    {
    };

    template <typename SourceType, typename TargetType>
    struct BoundsRangeConvertible<SourceType, TargetType, 0> : std::true_type
    {
    };

    template <std::ptrdiff_t... Ranges,
              typename = std::enable_if_t<details::BoundsRangeConvertible<
                  details::BoundsRanges<Ranges...>,
                  details::BoundsRanges<FirstRange, RestRanges...>>::value>>
    constexpr static_bounds(const static_bounds<Ranges...>& other) : m_ranges(other.m_ranges)
    {
        Expects((MyRanges::DynamicNum == 0 && details::BoundsRanges<Ranges...>::DynamicNum == 0) ||
                MyRanges::DynamicNum > 0 || other.m_ranges.totalSize() >= m_ranges.totalSize());
    }

    constexpr static_bounds(std::initializer_list<size_type> il) : m_ranges(il.begin())
    {
        // Size of the initializer list must match the rank of the array
        Expects((MyRanges::DynamicNum == 0 && il.size() == 1 && *il.begin() == static_size) ||
                MyRanges::DynamicNum == il.size());
        // Size of the range must be less than the max element of the size type
        Expects(m_ranges.totalSize() <= PTRDIFF_MAX);
    }

    constexpr sliced_type slice() const noexcept
    {
        return sliced_type{static_cast<const details::BoundsRanges<RestRanges...>&>(m_ranges)};
    }

    constexpr size_type stride() const noexcept { return rank > 1 ? slice().size() : 1; }

    constexpr size_type size() const noexcept { return m_ranges.totalSize(); }

    constexpr size_type total_size() const noexcept { return m_ranges.totalSize(); }

    constexpr size_type linearize(const index_type& idx) const { return m_ranges.linearize(idx); }

    constexpr bool contains(const index_type& idx) const noexcept
    {
        return m_ranges.contains(idx) != -1;
    }

    constexpr size_type operator[](std::size_t idx) const noexcept
    {
        return m_ranges.elementNum(idx);
    }

    template <std::size_t Dim = 0>
    constexpr size_type extent() const noexcept
    {
        static_assert(Dim < rank,
                      "dimension should be less than rank (dimension count starts from 0)");
        return details::createTypeListIndexer(m_ranges).template get<Dim>().elementNum();
    }

    template <typename IntType>
    constexpr size_type extent(IntType dim) const
    {
        static_assert(std::is_integral<IntType>::value,
                      "Dimension parameter must be supplied as an integral type.");
        auto real_dim = narrow_cast<std::size_t>(dim);
        Expects(real_dim < rank);

        return m_ranges.elementNum(real_dim);
    }

    constexpr index_type index_bounds() const noexcept
    {
        size_type extents[rank] = {};
        m_ranges.serialize(extents);
        return {extents};
    }

    template <std::ptrdiff_t... Ranges>
    constexpr bool operator==(const static_bounds<Ranges...>& rhs) const noexcept
    {
        return this->size() == rhs.size();
    }

    template <std::ptrdiff_t... Ranges>
    constexpr bool operator!=(const static_bounds<Ranges...>& rhs) const noexcept
    {
        return !(*this == rhs);
    }

    constexpr const_iterator begin() const noexcept
    {
        return const_iterator(*this, index_type{});
    }

    constexpr const_iterator end() const noexcept
    {
        return const_iterator(*this, this->index_bounds());
    }
};

template <std::size_t Rank>
class strided_bounds {
    template <std::size_t OtherRank>
    friend class strided_bounds;

public:
    static const std::size_t rank = Rank;
    using value_type = std::ptrdiff_t;
    using reference = std::add_lvalue_reference_t<value_type>;
    using const_reference = std::add_const_t<reference>;
    using size_type = value_type;
    using difference_type = value_type;
    using index_type = multi_span_index<rank>;
    using const_index_type = std::add_const_t<index_type>;
    using iterator = bounds_iterator<const_index_type>;
    using const_iterator = bounds_iterator<const_index_type>;
    static const value_type dynamic_rank = rank;
    static const value_type static_size = dynamic_range;
    using sliced_type = std::conditional_t<rank != 0, strided_bounds<rank - 1>, void>;
    using mapping_type = generalized_mapping_tag;

    constexpr strided_bounds(const strided_bounds&) noexcept = default;

    constexpr strided_bounds& operator=(const strided_bounds&) noexcept = default;

    constexpr strided_bounds(const value_type (&values)[rank], index_type strides)
        : m_extents(values), m_strides(std::move(strides))
    {}

    constexpr strided_bounds(const index_type& extents, const index_type& strides) noexcept
        : m_extents(extents), m_strides(strides)
    {
    }

    constexpr index_type strides() const noexcept { return m_strides; }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr size_type total_size() const noexcept
    {
        size_type ret = 0;
        for (std::size_t i = 0; i < rank; ++i) { ret += (m_extents[i] - 1) * m_strides[i]; }
        return ret + 1;
    }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr size_type size() const noexcept
    {
        size_type ret = 1;
        for (std::size_t i = 0; i < rank; ++i) { ret *= m_extents[i]; }
        return ret;
    }

    constexpr bool contains(const index_type& idx) const noexcept
    {
        for (std::size_t i = 0; i < rank; ++i)
        {
            if (idx[i] < 0 || idx[i] >= m_extents[i]) return false;
        }
        return true;
    }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr size_type linearize(const index_type& idx) const
    {
        size_type ret = 0;
        for (std::size_t i = 0; i < rank; i++)
        {
            Expects(idx[i] < m_extents[i]); // index is out of bounds of the array
            ret += idx[i] * m_strides[i];
        }
        return ret;
    }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr size_type stride() const noexcept { return m_strides[0]; }

    template <bool Enabled = (rank > 1), typename Ret = std::enable_if_t<Enabled, sliced_type>>
    constexpr sliced_type slice() const
    {
        return {details::shift_left(m_extents), details::shift_left(m_strides)};
    }

    template <std::size_t Dim = 0>

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr size_type extent() const noexcept
    {
        static_assert(Dim < Rank,
                      "dimension should be less than rank (dimension count starts from 0)");
        return m_extents[Dim];
    }

    constexpr index_type index_bounds() const noexcept { return m_extents; }

    constexpr const_iterator begin() const noexcept { return const_iterator{*this, index_type{}}; }

    constexpr const_iterator end() const noexcept { return const_iterator{*this, index_bounds()}; }

private:
    index_type m_extents;
    index_type m_strides;
};

template <typename T>
struct is_bounds : std::integral_constant<bool, false>
{
};
template <std::ptrdiff_t... Ranges>
struct is_bounds<static_bounds<Ranges...>> : std::integral_constant<bool, true>
{
};
template <std::size_t Rank>
struct is_bounds<strided_bounds<Rank>> : std::integral_constant<bool, true>
{
};

template <typename IndexType>
class bounds_iterator
{
public:
    static const std::size_t rank = IndexType::rank;
    using iterator_category = std::random_access_iterator_tag;
    using value_type = IndexType;
    using difference_type = std::ptrdiff_t;
    using pointer = value_type*;
    using reference = value_type&;
    using index_type = value_type;
    using index_size_type = typename IndexType::value_type;
    template <typename Bounds>
    explicit bounds_iterator(const Bounds& bnd, value_type curr) noexcept
        : boundary_(bnd.index_bounds()), curr_(std::move(curr))
    {
        static_assert(is_bounds<Bounds>::value, "Bounds type must be provided");
    }

    constexpr reference operator*() const noexcept { return curr_; }

    constexpr pointer operator->() const noexcept { return &curr_; }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
    constexpr bounds_iterator& operator++() noexcept

    {
        for (std::size_t i = rank; i-- > 0;)
        {
            if (curr_[i] < boundary_[i] - 1)
            {
                curr_[i]++;
                return *this;
            }
            curr_[i] = 0;
        }
        // If we're here we've wrapped over - set to past-the-end.
        curr_ = boundary_;
        return *this;
    }

    constexpr bounds_iterator operator++(int) noexcept
    {
        auto ret = *this;
        ++(*this);
        return ret;
    }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr bounds_iterator& operator--()
    {
        if (!less(curr_, boundary_))
        {
            // if at the past-the-end, set to last element
            for (std::size_t i = 0; i < rank; ++i) { curr_[i] = boundary_[i] - 1; }
            return *this;
        }
        for (std::size_t i = rank; i-- > 0;)
        {
            if (curr_[i] >= 1)
            {
                curr_[i]--;
                return *this;
            }
            curr_[i] = boundary_[i] - 1;
        }
        // If we're here the preconditions were violated
        // "pre: there exists s such that r == ++s"
        Expects(false);
        return *this;
    }

    constexpr bounds_iterator operator--(int) noexcept
    {
        auto ret = *this;
        --(*this);
        return ret;
    }

    constexpr bounds_iterator operator+(difference_type n) const noexcept
    {
        bounds_iterator ret{*this};
        return ret += n;
    }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr bounds_iterator& operator+=(difference_type n)
    {
        auto linear_idx = linearize(curr_) + n;
        std::remove_const_t<value_type> stride = 0;
        stride[rank - 1] = 1;
        for (std::size_t i = rank - 1; i-- > 0;) { stride[i] = stride[i + 1] * boundary_[i + 1]; }
        for (std::size_t i = 0; i < rank; ++i)
        {
            curr_[i] = linear_idx / stride[i];
            linear_idx = linear_idx % stride[i];
        }
        // index is out of bounds of the array
        Expects(!less(curr_, index_type{}) && !less(boundary_, curr_));
        return *this;
    }

    constexpr bounds_iterator operator-(difference_type n) const noexcept
    {
        bounds_iterator ret{*this};
        return ret -= n;
    }

    constexpr bounds_iterator& operator-=(difference_type n) noexcept { return *this += -n; }

    constexpr difference_type operator-(const bounds_iterator& rhs) const noexcept
    {
        return linearize(curr_) - linearize(rhs.curr_);
    }

    constexpr value_type operator[](difference_type n) const noexcept { return *(*this + n); }

    constexpr bool operator==(const bounds_iterator& rhs) const noexcept
    {
        return curr_ == rhs.curr_;
    }


    constexpr bool operator!=(const bounds_iterator& rhs) const noexcept { return !(*this == rhs); }

    constexpr bool operator<(const bounds_iterator& rhs) const noexcept
    {
        return less(curr_, rhs.curr_);
    }

    constexpr bool operator<=(const bounds_iterator& rhs) const noexcept { return !(rhs < *this); }

    constexpr bool operator>(const bounds_iterator& rhs) const noexcept { return rhs < *this; }

    constexpr bool operator>=(const bounds_iterator& rhs) const noexcept { return !(rhs > *this); }

    void swap(bounds_iterator& rhs) noexcept
    {
        std::swap(boundary_, rhs.boundary_);
        std::swap(curr_, rhs.curr_);
    }

private:

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr bool less(index_type& one, index_type& other) const noexcept
    {
        for (std::size_t i = 0; i < rank; ++i)
        {
            if (one[i] < other[i]) return true;
        }
        return false;
    }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    constexpr index_size_type linearize(const value_type& idx) const noexcept
    {
        // TODO: Smarter impl.
        // Check if past-the-end
        index_size_type multiplier = 1;
        index_size_type res = 0;
        if (!less(idx, boundary_))
        {
            res = 1;
            for (std::size_t i = rank; i-- > 0;)
            {
                res += (idx[i] - 1) * multiplier;
                multiplier *= boundary_[i];
            }
        }
        else
        {
            for (std::size_t i = rank; i-- > 0;)
            {
                res += idx[i] * multiplier;
                multiplier *= boundary_[i];
            }
        }
        return res;
    }

    value_type boundary_;
    std::remove_const_t<value_type> curr_;
};

template <typename IndexType>
bounds_iterator<IndexType> operator+(typename bounds_iterator<IndexType>::difference_type n,
                                     const bounds_iterator<IndexType>& rhs) noexcept
{
    return rhs + n;
}

namespace details
{
    template <typename Bounds>
    constexpr std::enable_if_t<
        std::is_same<typename Bounds::mapping_type, generalized_mapping_tag>::value,
        typename Bounds::index_type>
    make_stride(const Bounds& bnd) noexcept
    {
        return bnd.strides();
    }

    // Make a stride vector from bounds, assuming contiguous memory.
    template <typename Bounds>
    constexpr std::enable_if_t<
        std::is_same<typename Bounds::mapping_type, contiguous_mapping_tag>::value,
        typename Bounds::index_type>
    make_stride(const Bounds& bnd) noexcept
    {
        auto extents = bnd.index_bounds();
        typename Bounds::size_type stride[Bounds::rank] = {};

        stride[Bounds::rank - 1] = 1;
        for (std::size_t i = 1; i < Bounds::rank; ++i)
        {
            GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
            GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
            stride[Bounds::rank - i - 1] = stride[Bounds::rank - i] * extents[Bounds::rank - i];
        }
        return {stride};
    }

    template <typename BoundsSrc, typename BoundsDest>
    void verifyBoundsReshape(const BoundsSrc& src, const BoundsDest& dest)
    {
        static_assert(is_bounds<BoundsSrc>::value && is_bounds<BoundsDest>::value,
                      "The src type and dest type must be bounds");
        static_assert(std::is_same<typename BoundsSrc::mapping_type, contiguous_mapping_tag>::value,
                      "The source type must be a contiguous bounds");
        static_assert(BoundsDest::static_size == dynamic_range ||
                          BoundsSrc::static_size == dynamic_range ||
                          BoundsDest::static_size == BoundsSrc::static_size,
                      "The source bounds must have same size as dest bounds");
        Expects(src.size() == dest.size());
    }

} // namespace details

template <typename Span>
class contiguous_span_iterator;
template <typename Span>
class general_span_iterator;

template <std::ptrdiff_t DimSize = dynamic_range>
struct dim_t
{
    static const std::ptrdiff_t value = DimSize;
};
template <>
struct dim_t<dynamic_range>
{
    static const std::ptrdiff_t value = dynamic_range;
    const std::ptrdiff_t dvalue;
    constexpr dim_t(std::ptrdiff_t size) noexcept : dvalue(size) {}
};

template <std::ptrdiff_t N, class = std::enable_if_t<(N >= 0)>>
constexpr dim_t<N> dim() noexcept
{
    return dim_t<N>();
}

template <std::ptrdiff_t N = dynamic_range, class = std::enable_if_t<N == dynamic_range>>
constexpr dim_t<N> dim(std::ptrdiff_t n) noexcept
{
    return dim_t<>(n);
}

template <typename ValueType, std::ptrdiff_t FirstDimension = dynamic_range,
          std::ptrdiff_t... RestDimensions>
class multi_span;
template <typename ValueType, std::size_t Rank>
class strided_span;

namespace details
{
    template <typename T, typename = std::true_type>
    struct SpanTypeTraits
    {
        using value_type = T;
        using size_type = std::size_t;
    };

    template <typename Traits>
    struct SpanTypeTraits<Traits, typename std::is_reference<typename Traits::span_traits&>::type>
    {
        using value_type = typename Traits::span_traits::value_type;
        using size_type = typename Traits::span_traits::size_type;
    };

    template <typename T, std::ptrdiff_t... Ranks>
    struct SpanArrayTraits
    {
        using type = multi_span<T, Ranks...>;
        using value_type = T;
        using bounds_type = static_bounds<Ranks...>;
        using pointer = T*;
        using reference = T&;
    };
    template <typename T, std::ptrdiff_t N, std::ptrdiff_t... Ranks>
    struct SpanArrayTraits<T[N], Ranks...> : SpanArrayTraits<T, Ranks..., N>
    {
    };

    template <typename BoundsType>
    BoundsType newBoundsHelperImpl(std::ptrdiff_t totalSize, std::true_type) // dynamic size
    {
        Expects(totalSize >= 0 && totalSize <= PTRDIFF_MAX);
        return BoundsType{totalSize};
    }
    template <typename BoundsType>
    BoundsType newBoundsHelperImpl(std::ptrdiff_t totalSize, std::false_type) // static size
    {
        Expects(BoundsType::static_size <= totalSize);
        return {};
    }
    template <typename BoundsType>
    BoundsType newBoundsHelper(std::ptrdiff_t totalSize)
    {
        static_assert(BoundsType::dynamic_rank <= 1, "dynamic rank must less or equal to 1");
        return newBoundsHelperImpl<BoundsType>(
            totalSize, std::integral_constant<bool, BoundsType::dynamic_rank == 1>());
    }

    struct Sep
    {
    };

    template <typename T, typename... Args>
    T static_as_multi_span_helper(Sep, Args... args)
    {
        return T{narrow_cast<typename T::size_type>(args)...};
    }
    template <typename T, typename Arg, typename... Args>
    std::enable_if_t<
        !std::is_same<Arg, dim_t<dynamic_range>>::value && !std::is_same<Arg, Sep>::value, T>
    static_as_multi_span_helper(Arg, Args... args)
    {
        return static_as_multi_span_helper<T>(args...);
    }
    template <typename T, typename... Args>
    T static_as_multi_span_helper(dim_t<dynamic_range> val, Args... args)
    {
        return static_as_multi_span_helper<T>(args..., val.dvalue);
    }

    template <typename... Dimensions>
    struct static_as_multi_span_static_bounds_helper
    {
        using type = static_bounds<(Dimensions::value)...>;
    };

    template <typename T>
    struct is_multi_span_oracle : std::false_type
    {
    };

    template <typename ValueType, std::ptrdiff_t FirstDimension, std::ptrdiff_t... RestDimensions>
    struct is_multi_span_oracle<multi_span<ValueType, FirstDimension, RestDimensions...>>
        : std::true_type
    {
    };

    template <typename ValueType, std::ptrdiff_t Rank>
    struct is_multi_span_oracle<strided_span<ValueType, Rank>> : std::true_type
    {
    };

    template <typename T>
    struct is_multi_span : is_multi_span_oracle<std::remove_cv_t<T>>
    {
    };
} // namespace details

template <typename ValueType, std::ptrdiff_t FirstDimension, std::ptrdiff_t... RestDimensions>
class multi_span
{
    // TODO do we still need this?
    template <typename ValueType2, std::ptrdiff_t FirstDimension2,
              std::ptrdiff_t... RestDimensions2>
    friend class multi_span;

public:
    using bounds_type = static_bounds<FirstDimension, RestDimensions...>;
    static const std::size_t Rank = bounds_type::rank;
    using size_type = typename bounds_type::size_type;
    using index_type = typename bounds_type::index_type;
    using value_type = ValueType;
    using const_value_type = std::add_const_t<value_type>;
    using pointer = std::add_pointer_t<value_type>;
    using reference = std::add_lvalue_reference_t<value_type>;
    using iterator = contiguous_span_iterator<multi_span>;
    using const_span = multi_span<const_value_type, FirstDimension, RestDimensions...>;
    using const_iterator = contiguous_span_iterator<const_span>;
    using reverse_iterator = std::reverse_iterator<iterator>;
    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
    using sliced_type =
        std::conditional_t<Rank == 1, value_type, multi_span<value_type, RestDimensions...>>;

private:
    pointer data_;
    bounds_type bounds_;

    friend iterator;
    friend const_iterator;

public:
    // default constructor - same as constructing from nullptr_t
    GSL_SUPPRESS(type.6) // NO-FORMAT: attribute // TODO: false positive
    constexpr multi_span() noexcept
        : multi_span(nullptr, bounds_type{})
    {
        static_assert(bounds_type::dynamic_rank != 0 ||
                          (bounds_type::dynamic_rank == 0 && bounds_type::static_size == 0),
                      "Default construction of multi_span<T> only possible "
                      "for dynamic or fixed, zero-length spans.");
    }

    // construct from nullptr - get an empty multi_span
    GSL_SUPPRESS(type.6) // NO-FORMAT: attribute // TODO: false positive
    constexpr multi_span(std::nullptr_t) noexcept
        : multi_span(nullptr, bounds_type{})
    {
        static_assert(bounds_type::dynamic_rank != 0 ||
                          (bounds_type::dynamic_rank == 0 && bounds_type::static_size == 0),
                      "nullptr_t construction of multi_span<T> only possible "
                      "for dynamic or fixed, zero-length spans.");
    }

    // construct from nullptr with size of 0 (helps with template function calls)
    template <class IntType, typename = std::enable_if_t<std::is_integral<IntType>::value>>

    // GSL_SUPPRESS(type.6) // NO-FORMAT: attribute // TODO: false positive // TODO: parser bug
    constexpr multi_span(std::nullptr_t, IntType size) : multi_span(nullptr, bounds_type{})
    {
        static_assert(bounds_type::dynamic_rank != 0 ||
                          (bounds_type::dynamic_rank == 0 && bounds_type::static_size == 0),
                      "nullptr_t construction of multi_span<T> only possible "
                      "for dynamic or fixed, zero-length spans.");
        Expects(size == 0);
    }

    // construct from a single element

    GSL_SUPPRESS(type.6) // NO-FORMAT: attribute // TODO: false positive
    constexpr multi_span(reference data) noexcept
        : multi_span(&data, bounds_type{1})
    {
        static_assert(bounds_type::dynamic_rank > 0 || bounds_type::static_size == 0 ||
                          bounds_type::static_size == 1,
                      "Construction from a single element only possible "
                      "for dynamic or fixed spans of length 0 or 1.");
    }

    // prevent constructing from temporaries for single-elements
    constexpr multi_span(value_type&&) = delete;

    // construct from pointer + length
    GSL_SUPPRESS(type.6) // NO-FORMAT: attribute // TODO: false positive
    constexpr multi_span(pointer ptr, size_type size)
        : multi_span(ptr, bounds_type{size})
    {}

    // construct from pointer + length - multidimensional
    constexpr multi_span(pointer data, bounds_type bounds)
        : data_(data), bounds_(std::move(bounds))
    {
        Expects((bounds_.size() > 0 && data != nullptr) || bounds_.size() == 0);
    }

    // construct from begin,end pointer pair
    template <typename Ptr,
              typename = std::enable_if_t<std::is_convertible<Ptr, pointer>::value &&
                                          details::LessThan<bounds_type::dynamic_rank, 2>::value>>
    constexpr multi_span(pointer begin, Ptr end)
        : multi_span(begin,
                     details::newBoundsHelper<bounds_type>(static_cast<pointer>(end) - begin))
    {
        Expects(begin != nullptr && end != nullptr && begin <= static_cast<pointer>(end));
    }

    // construct from n-dimensions static array
    template <typename T, std::size_t N, typename Helper = details::SpanArrayTraits<T, N>>
    constexpr multi_span(T (&arr)[N])
        : multi_span(reinterpret_cast<pointer>(arr), bounds_type{typename Helper::bounds_type{}})
    {
        static_assert(std::is_convertible<typename Helper::value_type(*)[], value_type(*)[]>::value,
                      "Cannot convert from source type to target multi_span type.");
        static_assert(std::is_convertible<typename Helper::bounds_type, bounds_type>::value,
                      "Cannot construct a multi_span from an array with fewer elements.");
    }

    // construct from n-dimensions dynamic array (e.g. new int[m][4])
    // (precedence will be lower than the 1-dimension pointer)
    template <typename T, typename Helper = details::SpanArrayTraits<T, dynamic_range>>
    constexpr multi_span(T* const& data, size_type size)
        : multi_span(reinterpret_cast<pointer>(data), typename Helper::bounds_type{size})
    {
        static_assert(std::is_convertible<typename Helper::value_type(*)[], value_type(*)[]>::value,
                      "Cannot convert from source type to target multi_span type.");
    }

    // construct from std::array
    template <typename T, std::size_t N>
    constexpr multi_span(std::array<T, N>& arr)
        : multi_span(arr.data(), bounds_type{static_bounds<N>{}})
    {
        static_assert(
            std::is_convertible<T(*)[], typename std::remove_const_t<value_type>(*)[]>::value,
            "Cannot convert from source type to target multi_span type.");
        static_assert(std::is_convertible<static_bounds<N>, bounds_type>::value,
                      "You cannot construct a multi_span from a std::array of smaller size.");
    }

    // construct from const std::array
    template <typename T, std::size_t N>
    constexpr multi_span(const std::array<T, N>& arr)
        : multi_span(arr.data(), bounds_type{static_bounds<N>{}})
    {
        static_assert(
            std::is_convertible<T(*)[], typename std::remove_const_t<value_type>(*)[]>::value,
            "Cannot convert from source type to target multi_span type.");
        static_assert(std::is_convertible<static_bounds<N>, bounds_type>::value,
                      "You cannot construct a multi_span from a std::array of smaller size.");
    }

    // prevent constructing from temporary std::array
    template <typename T, std::size_t N>
    constexpr multi_span(std::array<T, N>&& arr) = delete;

    // construct from containers
    // future: could use contiguous_iterator_traits to identify only contiguous containers
    // type-requirements: container must have .size(), operator[] which are value_type compatible
    template <typename Cont, typename DataType = typename Cont::value_type,
              typename = std::enable_if_t<
                  !details::is_multi_span<Cont>::value &&
                  std::is_convertible<DataType (*)[], value_type (*)[]>::value &&
                  std::is_same<std::decay_t<decltype(std::declval<Cont>().size(),
                                                     *std::declval<Cont>().data())>,
                               DataType>::value>>
    constexpr multi_span(Cont& cont)
        : multi_span(static_cast<pointer>(cont.data()),
                     details::newBoundsHelper<bounds_type>(narrow_cast<size_type>(cont.size())))
    {}

    // prevent constructing from temporary containers
    template <typename Cont, typename DataType = typename Cont::value_type,
              typename = std::enable_if_t<
                  !details::is_multi_span<Cont>::value &&
                  std::is_convertible<DataType (*)[], value_type (*)[]>::value &&
                  std::is_same<std::decay_t<decltype(std::declval<Cont>().size(),
                                                     *std::declval<Cont>().data())>,
                               DataType>::value>>
    explicit constexpr multi_span(Cont&& cont) = delete;

    // construct from a convertible multi_span
    template <typename OtherValueType, std::ptrdiff_t... OtherDimensions,
              typename OtherBounds = static_bounds<OtherDimensions...>,
              typename = std::enable_if_t<std::is_convertible<OtherValueType, ValueType>::value &&
                                          std::is_convertible<OtherBounds, bounds_type>::value>>
    constexpr multi_span(multi_span<OtherValueType, OtherDimensions...> other)
        : data_(other.data_), bounds_(other.bounds_)
    {}

    // trivial copy and move
    constexpr multi_span(const multi_span&) = default;
    constexpr multi_span(multi_span&&) = default;

    // trivial assignment
    constexpr multi_span& operator=(const multi_span&) = default;
    constexpr multi_span& operator=(multi_span&&) = default;

    // first() - extract the first Count elements into a new multi_span
    template <std::ptrdiff_t Count>

    constexpr multi_span<ValueType, Count> first() const
    {
        static_assert(Count >= 0, "Count must be >= 0.");
        static_assert(bounds_type::static_size == dynamic_range ||
                          Count <= bounds_type::static_size,
                      "Count is out of bounds.");

        Expects(bounds_type::static_size != dynamic_range || Count <= this->size());
        return {this->data(), Count};
    }

    // first() - extract the first count elements into a new multi_span
    constexpr multi_span<ValueType, dynamic_range> first(size_type count) const
    {
        Expects(count >= 0 && count <= this->size());
        return {this->data(), count};
    }

    // last() - extract the last Count elements into a new multi_span
    template <std::ptrdiff_t Count>
    constexpr multi_span<ValueType, Count> last() const
    {
        static_assert(Count >= 0, "Count must be >= 0.");
        static_assert(bounds_type::static_size == dynamic_range ||
                          Count <= bounds_type::static_size,
                      "Count is out of bounds.");

        Expects(bounds_type::static_size != dynamic_range || Count <= this->size());
        return {this->data() + this->size() - Count, Count};
    }

    // last() - extract the last count elements into a new multi_span
    constexpr multi_span<ValueType, dynamic_range> last(size_type count) const
    {
        Expects(count >= 0 && count <= this->size());
        return {this->data() + this->size() - count, count};
    }

    // subspan() - create a subview of Count elements starting at Offset
    template <std::ptrdiff_t Offset, std::ptrdiff_t Count>
    constexpr multi_span<ValueType, Count> subspan() const
    {
        static_assert(Count >= 0, "Count must be >= 0.");
        static_assert(Offset >= 0, "Offset must be >= 0.");
        static_assert(bounds_type::static_size == dynamic_range ||
                          ((Offset <= bounds_type::static_size) &&
                           Count <= bounds_type::static_size - Offset),
                      "You must describe a sub-range within bounds of the multi_span.");

        Expects(bounds_type::static_size != dynamic_range ||
                (Offset <= this->size() && Count <= this->size() - Offset));
        return {this->data() + Offset, Count};
    }

    // subspan() - create a subview of count elements starting at offset
    // supplying dynamic_range for count will consume all available elements from offset
    constexpr multi_span<ValueType, dynamic_range> subspan(size_type offset,
                                                           size_type count = dynamic_range) const
    {
        Expects((offset >= 0 && offset <= this->size()) &&
                (count == dynamic_range || (count <= this->size() - offset)));
        return {this->data() + offset, count == dynamic_range ? this->length() - offset : count};
    }

    // section - creates a non-contiguous, strided multi_span from a contiguous one
    constexpr strided_span<ValueType, Rank> section(index_type origin,
                                                    index_type extents) const
    {
        const size_type size = this->bounds().total_size() - this->bounds().linearize(origin);
        return {&this->operator[](origin), size,
                strided_bounds<Rank>{extents, details::make_stride(bounds())}};
    }

    // length of the multi_span in elements
    constexpr size_type size() const noexcept { return bounds_.size(); }

    // length of the multi_span in elements
    constexpr size_type length() const noexcept { return this->size(); }

    // length of the multi_span in bytes
    constexpr size_type size_bytes() const noexcept
    {
        return narrow_cast<size_type>(sizeof(value_type)) * this->size();
    }

    // length of the multi_span in bytes
    constexpr size_type length_bytes() const noexcept { return this->size_bytes(); }

    constexpr bool empty() const noexcept { return this->size() == 0; }

    static constexpr std::size_t rank() { return Rank; }

    template <std::size_t Dim = 0>
    constexpr size_type extent() const noexcept
    {
        static_assert(Dim < Rank,
                      "Dimension should be less than rank (dimension count starts from 0).");
        return bounds_.template extent<Dim>();
    }

    template <typename IntType>
    constexpr size_type extent(IntType dim) const
    {
        return bounds_.extent(dim);
    }

    constexpr bounds_type bounds() const noexcept { return bounds_; }

    constexpr pointer data() const noexcept { return data_; }

    template <typename FirstIndex>
    constexpr reference operator()(FirstIndex idx)
    {
        return this->operator[](narrow_cast<std::ptrdiff_t>(idx));
    }

    template <typename FirstIndex, typename... OtherIndices>
    constexpr reference operator()(FirstIndex firstIndex, OtherIndices... indices)
    {
        const index_type idx = {narrow_cast<std::ptrdiff_t>(firstIndex),
                                narrow_cast<std::ptrdiff_t>(indices)...};
        return this->operator[](idx);
    }

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    constexpr reference operator[](const index_type& idx) const
    {
        return data_[bounds_.linearize(idx)];
    }

    template <bool Enabled = (Rank > 1), typename Ret = std::enable_if_t<Enabled, sliced_type>>

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    constexpr Ret operator[](size_type idx) const
    {
        Expects(idx >= 0 && idx < bounds_.size()); // index is out of bounds of the array
        const size_type ridx = idx * bounds_.stride();

        // index is out of bounds of the underlying data
        Expects(ridx < bounds_.total_size());
        return Ret{data_ + ridx, bounds_.slice()};
    }

    constexpr iterator begin() const noexcept { return iterator{this, true}; }

    constexpr iterator end() const noexcept { return iterator{this, false}; }

    GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
    constexpr const_iterator cbegin() const noexcept
    {
        return const_iterator{reinterpret_cast<const const_span*>(this), true};
    }

    constexpr const_iterator cend() const noexcept
    {
        return const_iterator{reinterpret_cast<const const_span*>(this), false};
    }

    constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator{end()}; }

    constexpr reverse_iterator rend() const noexcept { return reverse_iterator{begin()}; }

    constexpr const_reverse_iterator crbegin() const noexcept
    {
        return const_reverse_iterator{cend()};
    }

    constexpr const_reverse_iterator crend() const noexcept
    {
        return const_reverse_iterator{cbegin()};
    }

    template <typename OtherValueType, std::ptrdiff_t... OtherDimensions,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator==(const multi_span<OtherValueType, OtherDimensions...>& other) const
    {
        return bounds_.size() == other.bounds_.size() &&
               (data_ == other.data_ || std::equal(this->begin(), this->end(), other.begin()));
    }

    template <typename OtherValueType, std::ptrdiff_t... OtherDimensions,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator!=(const multi_span<OtherValueType, OtherDimensions...>& other) const
    {
        return !(*this == other);
    }

    template <typename OtherValueType, std::ptrdiff_t... OtherDimensions,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator<(const multi_span<OtherValueType, OtherDimensions...>& other) const
    {
        return std::lexicographical_compare(this->begin(), this->end(), other.begin(), other.end());
    }

    template <typename OtherValueType, std::ptrdiff_t... OtherDimensions,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator<=(const multi_span<OtherValueType, OtherDimensions...>& other) const
    {
        return !(other < *this);
    }

    template <typename OtherValueType, std::ptrdiff_t... OtherDimensions,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator>(const multi_span<OtherValueType, OtherDimensions...>& other) const
        noexcept
    {
        return (other < *this);
    }

    template <typename OtherValueType, std::ptrdiff_t... OtherDimensions,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator>=(const multi_span<OtherValueType, OtherDimensions...>& other) const
    {
        return !(*this < other);
    }
};

//
// Free functions for manipulating spans
//

// reshape a multi_span into a different dimensionality
// DimCount and Enabled here are workarounds for a bug in MSVC 2015
template <typename SpanType, typename... Dimensions2, std::size_t DimCount = sizeof...(Dimensions2),
          bool Enabled = (DimCount > 0), typename = std::enable_if_t<Enabled>>
constexpr auto as_multi_span(SpanType s, Dimensions2... dims)
    -> multi_span<typename SpanType::value_type, Dimensions2::value...>
{
    static_assert(details::is_multi_span<SpanType>::value,
                  "Variadic as_multi_span() is for reshaping existing spans.");
    using BoundsType =
        typename multi_span<typename SpanType::value_type, (Dimensions2::value)...>::bounds_type;
    const auto tobounds = details::static_as_multi_span_helper<BoundsType>(dims..., details::Sep{});
    details::verifyBoundsReshape(s.bounds(), tobounds);
    return {s.data(), tobounds};
}

// convert a multi_span<T> to a multi_span<const byte>
template <typename U, std::ptrdiff_t... Dimensions>
multi_span<const byte, dynamic_range> as_bytes(multi_span<U, Dimensions...> s) noexcept
{
    static_assert(std::is_trivial<std::decay_t<U>>::value,
                  "The value_type of multi_span must be a trivial type.");
    return {reinterpret_cast<const byte*>(s.data()), s.size_bytes()};
}

// convert a multi_span<T> to a multi_span<byte> (a writeable byte multi_span)
// this is not currently a portable function that can be relied upon to work
// on all implementations. It should be considered an experimental extension
// to the standard GSL interface.
template <typename U, std::ptrdiff_t... Dimensions>
multi_span<byte> as_writeable_bytes(multi_span<U, Dimensions...> s) noexcept
{
    static_assert(std::is_trivial<std::decay_t<U>>::value,
                  "The value_type of multi_span must be a trivial type.");
    return {reinterpret_cast<byte*>(s.data()), s.size_bytes()};
}

// convert a multi_span<const byte> to a multi_span<const T>
// this is not currently a portable function that can be relied upon to work
// on all implementations. It should be considered an experimental extension
// to the standard GSL interface.
template <typename U, std::ptrdiff_t... Dimensions>
constexpr auto as_multi_span(multi_span<const byte, Dimensions...> s) -> multi_span<
    const U, static_cast<std::ptrdiff_t>(
                 multi_span<const byte, Dimensions...>::bounds_type::static_size != dynamic_range
                     ? (static_cast<std::size_t>(
                            multi_span<const byte, Dimensions...>::bounds_type::static_size) /
                        sizeof(U))
                     : dynamic_range)>
{
    using ConstByteSpan = multi_span<const byte, Dimensions...>;
    static_assert(
        std::is_trivial<std::decay_t<U>>::value &&
            (ConstByteSpan::bounds_type::static_size == dynamic_range ||
             ConstByteSpan::bounds_type::static_size % narrow_cast<std::ptrdiff_t>(sizeof(U)) == 0),
        "Target type must be a trivial type and its size must match the byte array size");

    Expects((s.size_bytes() % narrow_cast<std::ptrdiff_t>(sizeof(U))) == 0 &&
            (s.size_bytes() / narrow_cast<std::ptrdiff_t>(sizeof(U))) < PTRDIFF_MAX);
    return {reinterpret_cast<const U*>(s.data()),
            s.size_bytes() / narrow_cast<std::ptrdiff_t>(sizeof(U))};
}

// convert a multi_span<byte> to a multi_span<T>
// this is not currently a portable function that can be relied upon to work
// on all implementations. It should be considered an experimental extension
// to the standard GSL interface.
template <typename U, std::ptrdiff_t... Dimensions>
constexpr auto as_multi_span(multi_span<byte, Dimensions...> s)
    -> multi_span<U, narrow_cast<std::ptrdiff_t>(
                         multi_span<byte, Dimensions...>::bounds_type::static_size != dynamic_range
                             ? static_cast<std::size_t>(
                                   multi_span<byte, Dimensions...>::bounds_type::static_size) /
                                   sizeof(U)
                             : dynamic_range)>
{
    using ByteSpan = multi_span<byte, Dimensions...>;
    static_assert(std::is_trivial<std::decay_t<U>>::value &&
                      (ByteSpan::bounds_type::static_size == dynamic_range ||
                       ByteSpan::bounds_type::static_size % sizeof(U) == 0),
                  "Target type must be a trivial type and its size must match the byte array size");

    Expects((s.size_bytes() % sizeof(U)) == 0);
    return {reinterpret_cast<U*>(s.data()),
            s.size_bytes() / narrow_cast<std::ptrdiff_t>(sizeof(U))};
}

template <typename T, std::ptrdiff_t... Dimensions>
constexpr auto as_multi_span(T* const& ptr, dim_t<Dimensions>... args)
    -> multi_span<std::remove_all_extents_t<T>, Dimensions...>
{
    return {reinterpret_cast<std::remove_all_extents_t<T>*>(ptr),
            details::static_as_multi_span_helper<static_bounds<Dimensions...>>(args...,
                                                                               details::Sep{})};
}

template <typename T>
constexpr auto as_multi_span(T* arr, std::ptrdiff_t len) ->
    typename details::SpanArrayTraits<T, dynamic_range>::type
{
    return {reinterpret_cast<std::remove_all_extents_t<T>*>(arr), len};
}

template <typename T, std::size_t N>
constexpr auto as_multi_span(T (&arr)[N]) -> typename details::SpanArrayTraits<T, N>::type
{
    return {arr};
}

template <typename T, std::size_t N>
constexpr multi_span<const T, N> as_multi_span(const std::array<T, N>& arr)
{
    return {arr};
}

template <typename T, std::size_t N>
constexpr multi_span<const T, N> as_multi_span(const std::array<T, N>&&) = delete;

template <typename T, std::size_t N>
constexpr multi_span<T, N> as_multi_span(std::array<T, N>& arr)
{
    return {arr};
}

template <typename T>
constexpr multi_span<T, dynamic_range> as_multi_span(T* begin, T* end)
{
    return {begin, end};
}

template <typename Cont>
constexpr auto as_multi_span(Cont& arr) -> std::enable_if_t<
    !details::is_multi_span<std::decay_t<Cont>>::value,
    multi_span<std::remove_reference_t<decltype(arr.size(), *arr.data())>, dynamic_range>>
{
    Expects(arr.size() < PTRDIFF_MAX);
    return {arr.data(), narrow_cast<std::ptrdiff_t>(arr.size())};
}

template <typename Cont>
constexpr auto as_multi_span(Cont&& arr) -> std::enable_if_t<
    !details::is_multi_span<std::decay_t<Cont>>::value,
    multi_span<std::remove_reference_t<decltype(arr.size(), *arr.data())>, dynamic_range>> = delete;

// from basic_string which doesn't have nonconst .data() member like other contiguous containers
template <typename CharT, typename Traits, typename Allocator>
GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
constexpr auto as_multi_span(std::basic_string<CharT, Traits, Allocator>& str)
    -> multi_span<CharT, dynamic_range>
{
    Expects(str.size() < PTRDIFF_MAX);
    return {&str[0], narrow_cast<std::ptrdiff_t>(str.size())};
}

// strided_span is an extension that is not strictly part of the GSL at this time.
// It is kept here while the multidimensional interface is still being defined.
template <typename ValueType, std::size_t Rank>
class strided_span
{
public:
    using bounds_type = strided_bounds<Rank>;
    using size_type = typename bounds_type::size_type;
    using index_type = typename bounds_type::index_type;
    using value_type = ValueType;
    using const_value_type = std::add_const_t<value_type>;
    using pointer = std::add_pointer_t<value_type>;
    using reference = std::add_lvalue_reference_t<value_type>;
    using iterator = general_span_iterator<strided_span>;
    using const_strided_span = strided_span<const_value_type, Rank>;
    using const_iterator = general_span_iterator<const_strided_span>;
    using reverse_iterator = std::reverse_iterator<iterator>;
    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
    using sliced_type =
        std::conditional_t<Rank == 1, value_type, strided_span<value_type, Rank - 1>>;

private:
    pointer data_;
    bounds_type bounds_;

    friend iterator;
    friend const_iterator;
    template <typename OtherValueType, std::size_t OtherRank>
    friend class strided_span;

public:
    // from raw data
    constexpr strided_span(pointer ptr, size_type size, bounds_type bounds)
        : data_(ptr), bounds_(std::move(bounds))
    {
        Expects((bounds_.size() > 0 && ptr != nullptr) || bounds_.size() == 0);
        // Bounds cross data boundaries
        Expects(this->bounds().total_size() <= size);
        GSL_SUPPRESS(type.4) // NO-FORMAT: attribute // TODO: false positive
        (void) size;
    }

    // from static array of size N
    template <size_type N>
    constexpr strided_span(value_type (&values)[N], bounds_type bounds)
        : strided_span(values, N, std::move(bounds))
    {}

    // from array view
    template <typename OtherValueType, std::ptrdiff_t... Dimensions,
              bool Enabled1 = (sizeof...(Dimensions) == Rank),
              bool Enabled2 = std::is_convertible<OtherValueType*, ValueType*>::value,
              typename = std::enable_if_t<Enabled1 && Enabled2>>
    constexpr strided_span(multi_span<OtherValueType, Dimensions...> av, bounds_type bounds)
        : strided_span(av.data(), av.bounds().total_size(), std::move(bounds))
    {}

    // convertible
    template <typename OtherValueType, typename = std::enable_if_t<std::is_convertible<
                                           OtherValueType (*)[], value_type (*)[]>::value>>
    constexpr strided_span(const strided_span<OtherValueType, Rank>& other)
        : data_(other.data_), bounds_(other.bounds_)
    {}

    // convert from bytes
    template <typename OtherValueType>
    constexpr strided_span<
        typename std::enable_if<std::is_same<value_type, const byte>::value, OtherValueType>::type,
        Rank>
    as_strided_span() const
    {
        static_assert((sizeof(OtherValueType) >= sizeof(value_type)) &&
                          (sizeof(OtherValueType) % sizeof(value_type) == 0),
                      "OtherValueType should have a size to contain a multiple of ValueTypes");
        auto d = narrow_cast<size_type>(sizeof(OtherValueType) / sizeof(value_type));

        const size_type size = this->bounds().total_size() / d;

        GSL_SUPPRESS(type.3) // NO-FORMAT: attribute
        return {const_cast<OtherValueType*>(reinterpret_cast<const OtherValueType*>(this->data())),
                size,
                bounds_type{resize_extent(this->bounds().index_bounds(), d),
                            resize_stride(this->bounds().strides(), d)}};
    }

    constexpr strided_span section(index_type origin, index_type extents) const
    {
        const size_type size = this->bounds().total_size() - this->bounds().linearize(origin);
        return {&this->operator[](origin), size,
                bounds_type{extents, details::make_stride(bounds())}};
    }

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    constexpr reference operator[](const index_type& idx) const
    {
        return data_[bounds_.linearize(idx)];
    }

    template <bool Enabled = (Rank > 1), typename Ret = std::enable_if_t<Enabled, sliced_type>>
    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    constexpr Ret operator[](size_type idx) const
    {
        Expects(idx < bounds_.size()); // index is out of bounds of the array
        const size_type ridx = idx * bounds_.stride();

        // index is out of bounds of the underlying data
        Expects(ridx < bounds_.total_size());
        return {data_ + ridx, bounds_.slice().total_size(), bounds_.slice()};
    }

    constexpr bounds_type bounds() const noexcept { return bounds_; }

    template <std::size_t Dim = 0>
    constexpr size_type extent() const noexcept
    {
        static_assert(Dim < Rank,
                      "dimension should be less than Rank (dimension count starts from 0)");
        return bounds_.template extent<Dim>();
    }

    constexpr size_type size() const noexcept { return bounds_.size(); }

    constexpr pointer data() const noexcept { return data_; }

    constexpr bool empty() const noexcept { return this->size() == 0; }

    constexpr explicit operator bool() const noexcept { return data_ != nullptr; }

    constexpr iterator begin() const { return iterator{this, true}; }

    constexpr iterator end() const { return iterator{this, false}; }

    constexpr const_iterator cbegin() const
    {
        return const_iterator{reinterpret_cast<const const_strided_span*>(this), true};
    }

    constexpr const_iterator cend() const
    {
        return const_iterator{reinterpret_cast<const const_strided_span*>(this), false};
    }

    constexpr reverse_iterator rbegin() const { return reverse_iterator{end()}; }

    constexpr reverse_iterator rend() const { return reverse_iterator{begin()}; }

    constexpr const_reverse_iterator crbegin() const { return const_reverse_iterator{cend()}; }

    constexpr const_reverse_iterator crend() const { return const_reverse_iterator{cbegin()}; }

    template <typename OtherValueType, std::ptrdiff_t OtherRank,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator==(const strided_span<OtherValueType, OtherRank>& other) const
    {
        return bounds_.size() == other.bounds_.size() &&
               (data_ == other.data_ || std::equal(this->begin(), this->end(), other.begin()));
    }

    template <typename OtherValueType, std::ptrdiff_t OtherRank,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator!=(const strided_span<OtherValueType, OtherRank>& other) const
    {
        return !(*this == other);
    }

    template <typename OtherValueType, std::ptrdiff_t OtherRank,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator<(const strided_span<OtherValueType, OtherRank>& other) const
    {
        return std::lexicographical_compare(this->begin(), this->end(), other.begin(), other.end());
    }

    template <typename OtherValueType, std::ptrdiff_t OtherRank,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator<=(const strided_span<OtherValueType, OtherRank>& other) const
    {
        return !(other < *this);
    }

    template <typename OtherValueType, std::ptrdiff_t OtherRank,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator>(const strided_span<OtherValueType, OtherRank>& other) const
    {
        return (other < *this);
    }

    template <typename OtherValueType, std::ptrdiff_t OtherRank,
              typename = std::enable_if_t<std::is_same<std::remove_cv_t<value_type>,
                                                       std::remove_cv_t<OtherValueType>>::value>>
    constexpr bool operator>=(const strided_span<OtherValueType, OtherRank>& other) const
    {
        return !(*this < other);
    }

private:
    static index_type resize_extent(const index_type& extent, std::ptrdiff_t d)
    {
        // The last dimension of the array needs to contain a multiple of new type elements
        GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
        Expects(extent[Rank - 1] >= d && (extent[Rank - 1] % d == 0));

        index_type ret = extent;
        ret[Rank - 1] /= d;

        return ret;
    }

    template <bool Enabled = (Rank == 1), typename = std::enable_if_t<Enabled>>
    static index_type resize_stride(const index_type& strides, std::ptrdiff_t, void* = nullptr)
    {
        // Only strided arrays with regular strides can be resized
        GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
        Expects(strides[Rank - 1] == 1);

        return strides;
    }

    template <bool Enabled = (Rank > 1), typename = std::enable_if_t<Enabled>>
    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    static index_type resize_stride(const index_type& strides, std::ptrdiff_t d)
    {
        // Only strided arrays with regular strides can be resized
        Expects(strides[Rank - 1] == 1);
        // The strides must have contiguous chunks of
        // memory that can contain a multiple of new type elements
        Expects(strides[Rank - 2] >= d && (strides[Rank - 2] % d == 0));

        for (std::size_t i = Rank - 1; i > 0; --i)
        {
            // Only strided arrays with regular strides can be resized
            Expects((strides[i - 1] >= strides[i]) && (strides[i - 1] % strides[i] == 0));
        }

        index_type ret = strides / d;
        ret[Rank - 1] = 1;

        return ret;
    }
};

template <class Span>
class contiguous_span_iterator
{
public:
    using iterator_category = std::random_access_iterator_tag;
    using value_type = typename Span::value_type;
    using difference_type = std::ptrdiff_t;
    using pointer = value_type*;
    using reference = value_type&;

private:
    template <typename ValueType, std::ptrdiff_t FirstDimension, std::ptrdiff_t... RestDimensions>
    friend class multi_span;

    pointer data_;
    const Span* m_validator;

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    void validateThis() const {
        // iterator is out of range of the array
        Expects(data_ >= m_validator->data_ && data_ < m_validator->data_ + m_validator->size());
    }

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    contiguous_span_iterator(const Span* container, bool isbegin)
        : data_(isbegin ? container->data_ : container->data_ + container->size())
        , m_validator(container)
    {}

public:
    reference operator*() const
    {
        validateThis();
        return *data_;
    }
    pointer operator->() const
    {
        validateThis();
        return data_;
    }

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    contiguous_span_iterator& operator++() noexcept
    {
        ++data_;
        return *this;
    }
    contiguous_span_iterator operator++(int) noexcept
    {
        auto ret = *this;
        ++(*this);
        return ret;
    }

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    contiguous_span_iterator& operator--() noexcept
    {
        --data_;
        return *this;
    }
    contiguous_span_iterator operator--(int) noexcept
    {
        auto ret = *this;
        --(*this);
        return ret;
    }
    contiguous_span_iterator operator+(difference_type n) const noexcept
    {
        contiguous_span_iterator ret{*this};
        return ret += n;
    }
    contiguous_span_iterator& operator+=(difference_type n) noexcept
    {
        data_ += n;
        return *this;
    }
    contiguous_span_iterator operator-(difference_type n) const noexcept
    {
        contiguous_span_iterator ret{*this};
        return ret -= n;
    }

    contiguous_span_iterator& operator-=(difference_type n) { return *this += -n; }
    difference_type operator-(const contiguous_span_iterator& rhs) const
    {
        Expects(m_validator == rhs.m_validator);
        return data_ - rhs.data_;
    }
    reference operator[](difference_type n) const { return *(*this + n); }
    bool operator==(const contiguous_span_iterator& rhs) const
    {
        Expects(m_validator == rhs.m_validator);
        return data_ == rhs.data_;
    }

    bool operator!=(const contiguous_span_iterator& rhs) const { return !(*this == rhs); }

    bool operator<(const contiguous_span_iterator& rhs) const
    {
        Expects(m_validator == rhs.m_validator);
        return data_ < rhs.data_;
    }

    bool operator<=(const contiguous_span_iterator& rhs) const { return !(rhs < *this); }
    bool operator>(const contiguous_span_iterator& rhs) const { return rhs < *this; }
    bool operator>=(const contiguous_span_iterator& rhs) const { return !(rhs > *this); }

    void swap(contiguous_span_iterator& rhs) noexcept
    {
        std::swap(data_, rhs.data_);
        std::swap(m_validator, rhs.m_validator);
    }
};

template <typename Span>
contiguous_span_iterator<Span> operator+(typename contiguous_span_iterator<Span>::difference_type n,
                                         const contiguous_span_iterator<Span>& rhs) noexcept
{
    return rhs + n;
}

template <typename Span>
class general_span_iterator {
public:
    using iterator_category = std::random_access_iterator_tag;
    using value_type = typename Span::value_type;
    using difference_type = std::ptrdiff_t;
    using pointer = value_type*;
    using reference = value_type&;

private:
    template <typename ValueType, std::size_t Rank>
    friend class strided_span;

    const Span* m_container;
    typename Span::bounds_type::iterator m_itr;
    general_span_iterator(const Span* container, bool isbegin)
        : m_container(container)
        , m_itr(isbegin ? m_container->bounds().begin() : m_container->bounds().end())
    {}

public:
    reference operator*() noexcept { return (*m_container)[*m_itr]; }
    pointer operator->() noexcept { return &(*m_container)[*m_itr]; }
    general_span_iterator& operator++() noexcept
    {
        ++m_itr;
        return *this;
    }
    general_span_iterator operator++(int) noexcept
    {
        auto ret = *this;
        ++(*this);
        return ret;
    }
    general_span_iterator& operator--() noexcept
    {
        --m_itr;
        return *this;
    }
    general_span_iterator operator--(int) noexcept
    {
        auto ret = *this;
        --(*this);
        return ret;
    }
    general_span_iterator operator+(difference_type n) const noexcept
    {
        general_span_iterator ret{*this};
        return ret += n;
    }
    general_span_iterator& operator+=(difference_type n) noexcept
    {
        m_itr += n;
        return *this;
    }
    general_span_iterator operator-(difference_type n) const noexcept
    {
        general_span_iterator ret{*this};
        return ret -= n;
    }
    general_span_iterator& operator-=(difference_type n) noexcept { return *this += -n; }
    difference_type operator-(const general_span_iterator& rhs) const
    {
        Expects(m_container == rhs.m_container);
        return m_itr - rhs.m_itr;
    }

    GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
    value_type operator[](difference_type n) const { return (*m_container)[m_itr[n]]; }

    bool operator==(const general_span_iterator& rhs) const
    {
        Expects(m_container == rhs.m_container);
        return m_itr == rhs.m_itr;
    }
    bool operator!=(const general_span_iterator& rhs) const { return !(*this == rhs); }
    bool operator<(const general_span_iterator& rhs) const
    {
        Expects(m_container == rhs.m_container);
        return m_itr < rhs.m_itr;
    }
    bool operator<=(const general_span_iterator& rhs) const { return !(rhs < *this); }
    bool operator>(const general_span_iterator& rhs) const { return rhs < *this; }
    bool operator>=(const general_span_iterator& rhs) const { return !(rhs > *this); }
    void swap(general_span_iterator& rhs) noexcept
    {
        std::swap(m_itr, rhs.m_itr);
        std::swap(m_container, rhs.m_container);
    }
};

template <typename Span>
general_span_iterator<Span> operator+(typename general_span_iterator<Span>::difference_type n,
                                      const general_span_iterator<Span>& rhs) noexcept
{
    return rhs + n;
}

} // namespace gsl

#if defined(_MSC_VER) && !defined(__clang__)
#if _MSC_VER < 1910

#undef constexpr
#pragma pop_macro("constexpr")
#endif // _MSC_VER < 1910

#pragma warning(pop)

#endif // _MSC_VER

#if defined(__GNUC__) && __GNUC__ > 6
#pragma GCC diagnostic pop
#endif // __GNUC__ > 6

#endif // GSL_MULTI_SPAN_H

D module-utils/gsl/pointers => module-utils/gsl/pointers +0 -294
@@ 1,294 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_POINTERS_H
#define GSL_POINTERS_H

#include <gsl/gsl_assert>  // for Ensures, Expects

#include <algorithm>    // for forward
#include <iosfwd>       // for ptrdiff_t, nullptr_t, ostream, size_t
#include <memory>       // for shared_ptr, unique_ptr
#include <system_error> // for hash
#include <type_traits>  // for enable_if_t, is_convertible, is_assignable

#if defined(_MSC_VER) && _MSC_VER < 1910 && !defined(__clang__)
#pragma push_macro("constexpr")
#define constexpr /*constexpr*/

#endif                          // defined(_MSC_VER) && _MSC_VER < 1910

namespace gsl
{

//
// GSL.owner: ownership pointers
//
using std::unique_ptr;
using std::shared_ptr;

//
// owner
//
// owner<T> is designed as a bridge for code that must deal directly with owning pointers for some reason
//
// T must be a pointer type
// - disallow construction from any type other than pointer type
//
template <class T, class = std::enable_if_t<std::is_pointer<T>::value>>
using owner = T;

//
// not_null
//
// Restricts a pointer or smart pointer to only hold non-null values.
//
// Has zero size overhead over T.
//
// If T is a pointer (i.e. T == U*) then
// - allow construction from U*
// - disallow construction from nullptr_t
// - disallow default construction
// - ensure construction from null U* fails
// - allow implicit conversion to U*
//
template <class T>
class not_null
{
public:
    static_assert(std::is_assignable<T&, std::nullptr_t>::value, "T cannot be assigned nullptr.");

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    constexpr not_null(U&& u) : ptr_(std::forward<U>(u))
    {
        Expects(ptr_ != nullptr);
    }

    template <typename = std::enable_if_t<!std::is_same<std::nullptr_t, T>::value>>
    constexpr not_null(T u) : ptr_(u)
    {
        Expects(ptr_ != nullptr);
    }

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    constexpr not_null(const not_null<U>& other) : not_null(other.get())
    {
    }

    not_null(not_null&& other) = default;
    not_null(const not_null& other) = default;
    not_null& operator=(const not_null& other) = default;

    constexpr T get() const
    {
        Ensures(ptr_ != nullptr);
        return ptr_;
    }

    constexpr operator T() const { return get(); }
    constexpr T operator->() const { return get(); }
    constexpr decltype(auto) operator*() const { return *get(); } 

    // prevents compilation when someone attempts to assign a null pointer constant
    not_null(std::nullptr_t) = delete;
    not_null& operator=(std::nullptr_t) = delete;

    // unwanted operators...pointers only point to single objects!
    not_null& operator++() = delete;
    not_null& operator--() = delete;
    not_null operator++(int) = delete;
    not_null operator--(int) = delete;
    not_null& operator+=(std::ptrdiff_t) = delete;
    not_null& operator-=(std::ptrdiff_t) = delete;
    void operator[](std::ptrdiff_t) const = delete;

private:
    T ptr_;
};

template <class T>
auto make_not_null(T&& t) {
    return not_null<std::remove_cv_t<std::remove_reference_t<T>>>{std::forward<T>(t)};
}

template <class T>
std::ostream& operator<<(std::ostream& os, const not_null<T>& val)
{
    os << val.get();
    return os;
}

template <class T, class U>
auto operator==(const not_null<T>& lhs, const not_null<U>& rhs) -> decltype(lhs.get() == rhs.get())
{
    return lhs.get() == rhs.get();
}

template <class T, class U>
auto operator!=(const not_null<T>& lhs, const not_null<U>& rhs) -> decltype(lhs.get() != rhs.get())
{
    return lhs.get() != rhs.get();
}

template <class T, class U>
auto operator<(const not_null<T>& lhs, const not_null<U>& rhs) -> decltype(lhs.get() < rhs.get())
{
    return lhs.get() < rhs.get();
}

template <class T, class U>
auto operator<=(const not_null<T>& lhs, const not_null<U>& rhs) -> decltype(lhs.get() <= rhs.get())
{
    return lhs.get() <= rhs.get();
}

template <class T, class U>
auto operator>(const not_null<T>& lhs, const not_null<U>& rhs) -> decltype(lhs.get() > rhs.get())
{
    return lhs.get() > rhs.get();
}

template <class T, class U>
auto operator>=(const not_null<T>& lhs, const not_null<U>& rhs) -> decltype(lhs.get() >= rhs.get())
{
    return lhs.get() >= rhs.get();
}

// more unwanted operators
template <class T, class U>
std::ptrdiff_t operator-(const not_null<T>&, const not_null<U>&) = delete;
template <class T>
not_null<T> operator-(const not_null<T>&, std::ptrdiff_t) = delete;
template <class T>
not_null<T> operator+(const not_null<T>&, std::ptrdiff_t) = delete;
template <class T>
not_null<T> operator+(std::ptrdiff_t, const not_null<T>&) = delete;

} // namespace gsl

namespace std
{
template <class T>
struct hash<gsl::not_null<T>>
{
    std::size_t operator()(const gsl::not_null<T>& value) const { return hash<T>{}(value); }
};

} // namespace std

namespace gsl
{

//
// strict_not_null
//
// Restricts a pointer or smart pointer to only hold non-null values,
//
// - provides a strict (i.e. explicit contructor from T) wrapper of not_null
// - to be used for new code that wishes the design to be cleaner and make not_null
//   checks intentional, or in old code that would like to make the transition.
//
//   To make the transition from not_null, incrementally replace not_null
//   by strict_not_null and fix compilation errors
//
//   Expect to
//   - remove all unneded conversions from raw pointer to not_null and back
//   - make API clear by specifyning not_null in parameters where needed
//   - remove unnesessary asserts
//
template <class T>
class strict_not_null: public not_null<T>
{
public:

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    constexpr explicit strict_not_null(U&& u) :
        not_null<T>(std::forward<U>(u))
    {}

    template <typename = std::enable_if_t<!std::is_same<std::nullptr_t, T>::value>>
    constexpr explicit strict_not_null(T u) :
        not_null<T>(u)
    {}

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    constexpr strict_not_null(const not_null<U>& other) :
        not_null<T>(other)
    {}

    template <typename U, typename = std::enable_if_t<std::is_convertible<U, T>::value>>
    constexpr strict_not_null(const strict_not_null<U>& other) :
        not_null<T>(other)
    {}

    strict_not_null(strict_not_null&& other) = default;
    strict_not_null(const strict_not_null& other) = default;
    strict_not_null& operator=(const strict_not_null& other) = default;
    strict_not_null& operator=(const not_null<T>& other)
    {
        not_null<T>::operator=(other);
        return *this;
    }

    // prevents compilation when someone attempts to assign a null pointer constant
    strict_not_null(std::nullptr_t) = delete;
    strict_not_null& operator=(std::nullptr_t) = delete;

    // unwanted operators...pointers only point to single objects!
    strict_not_null& operator++() = delete;
    strict_not_null& operator--() = delete;
    strict_not_null operator++(int) = delete;
    strict_not_null operator--(int) = delete;
    strict_not_null& operator+=(std::ptrdiff_t) = delete;
    strict_not_null& operator-=(std::ptrdiff_t) = delete;
    void operator[](std::ptrdiff_t) const = delete;
};

// more unwanted operators
template <class T, class U>
std::ptrdiff_t operator-(const strict_not_null<T>&, const strict_not_null<U>&) = delete;
template <class T>
strict_not_null<T> operator-(const strict_not_null<T>&, std::ptrdiff_t) = delete;
template <class T>
strict_not_null<T> operator+(const strict_not_null<T>&, std::ptrdiff_t) = delete;
template <class T>
strict_not_null<T> operator+(std::ptrdiff_t, const strict_not_null<T>&) = delete;

template <class T>
auto make_strict_not_null(T&& t) {
    return strict_not_null<std::remove_cv_t<std::remove_reference_t<T>>>{std::forward<T>(t)};
}

} // namespace gsl

namespace std
{
template <class T>
struct hash<gsl::strict_not_null<T>>
{
    std::size_t operator()(const gsl::strict_not_null<T>& value) const { return hash<T>{}(value); }
};

} // namespace std

#if defined(_MSC_VER) && _MSC_VER < 1910 && !defined(__clang__)

#undef constexpr
#pragma pop_macro("constexpr")

#endif // defined(_MSC_VER) && _MSC_VER < 1910 && !defined(__clang__)

#endif // GSL_POINTERS_H

D module-utils/gsl/span => module-utils/gsl/span +0 -793
@@ 1,793 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_SPAN_H
#define GSL_SPAN_H

#include <gsl/gsl_assert> // for Expects
#include <gsl/gsl_byte>   // for byte
#include <gsl/gsl_util>   // for narrow_cast, narrow

#include <algorithm> // for lexicographical_compare
#include <array>     // for array
#include <cstddef>   // for ptrdiff_t, size_t, nullptr_t
#include <iterator>  // for reverse_iterator, distance, random_access_...
#include <limits>
#include <stdexcept>
#include <type_traits> // for enable_if_t, declval, is_convertible, inte...
#include <utility>
#include <memory> // for std::addressof

#if defined(_MSC_VER) && !defined(__clang__)
#pragma warning(push)

// turn off some warnings that are noisy about our Expects statements
#pragma warning(disable : 4127) // conditional expression is constant
#pragma warning(disable : 4702) // unreachable code

// Turn MSVC /analyze rules that generate too much noise. TODO: fix in the tool.
#pragma warning(disable : 26495) // uninitalized member when constructor calls constructor
#pragma warning(disable : 26446) // parser bug does not allow attributes on some templates

#if _MSC_VER < 1910
#pragma push_macro("constexpr")
#define constexpr /*constexpr*/
#define GSL_USE_STATIC_CONSTEXPR_WORKAROUND

#endif // _MSC_VER < 1910
#endif // _MSC_VER

// See if we have enough C++17 power to use a static constexpr data member
// without needing an out-of-line definition
#if !(defined(__cplusplus) && (__cplusplus >= 201703L))
#define GSL_USE_STATIC_CONSTEXPR_WORKAROUND
#endif // !(defined(__cplusplus) && (__cplusplus >= 201703L))

// GCC 7 does not like the signed unsigned missmatch (size_t ptrdiff_t)
// While there is a conversion from signed to unsigned, it happens at
// compiletime, so the compiler wouldn't have to warn indiscriminently, but
// could check if the source value actually doesn't fit into the target type
// and only warn in those cases.
#if defined(__GNUC__) && __GNUC__ > 6
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsign-conversion"
#endif

namespace gsl
{

// [views.constants], constants
constexpr const std::ptrdiff_t dynamic_extent = -1;

template <class ElementType, std::ptrdiff_t Extent = dynamic_extent>
class span;

// implementation details
namespace details
{
    template <class T>
    struct is_span_oracle : std::false_type
    {
    };

    template <class ElementType, std::ptrdiff_t Extent>
    struct is_span_oracle<gsl::span<ElementType, Extent>> : std::true_type
    {
    };

    template <class T>
    struct is_span : public is_span_oracle<std::remove_cv_t<T>>
    {
    };

    template <class T>
    struct is_std_array_oracle : std::false_type
    {
    };

    template <class ElementType, std::size_t Extent>
    struct is_std_array_oracle<std::array<ElementType, Extent>> : std::true_type
    {
    };

    template <class T>
    struct is_std_array : public is_std_array_oracle<std::remove_cv_t<T>>
    {
    };

    template <std::ptrdiff_t From, std::ptrdiff_t To>
    struct is_allowed_extent_conversion
        : public std::integral_constant<bool, From == To || From == gsl::dynamic_extent ||
                                                  To == gsl::dynamic_extent>
    {
    };

    template <class From, class To>
    struct is_allowed_element_type_conversion
        : public std::integral_constant<bool, std::is_convertible<From (*)[], To (*)[]>::value>
    {
    };

    template <class Span, bool IsConst>
    class span_iterator
    {
        using element_type_ = typename Span::element_type;

    public:
#ifdef _MSC_VER
        // Tell Microsoft standard library that span_iterators are checked.
        using _Unchecked_type = typename Span::pointer;
#endif

        using iterator_category = std::random_access_iterator_tag;
        using value_type = std::remove_cv_t<element_type_>;
        using difference_type = typename Span::index_type;

        using reference = std::conditional_t<IsConst, const element_type_, element_type_>&;
        using pointer = std::add_pointer_t<reference>;

        span_iterator() = default;

        constexpr span_iterator(const Span* span, typename Span::index_type idx) noexcept
            : span_(span), index_(idx)
        {}

        friend span_iterator<Span, true>;
        template <bool B, std::enable_if_t<!B && IsConst>* = nullptr>
        constexpr span_iterator(const span_iterator<Span, B>& other) noexcept
            : span_iterator(other.span_, other.index_)
        {}

        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        constexpr reference operator*() const
        {
            Expects(index_ != span_->size());
            return *(span_->data() + index_);
        }

        constexpr pointer operator->() const
        {
            Expects(index_ != span_->size());
            return span_->data() + index_;
        }

        constexpr span_iterator& operator++()
        {
            Expects(0 <= index_ && index_ != span_->size());
            ++index_;
            return *this;
        }

        constexpr span_iterator operator++(int)
        {
            auto ret = *this;
            ++(*this);
            return ret;
        }

        constexpr span_iterator& operator--()
        {
            Expects(index_ != 0 && index_ <= span_->size());
            --index_;
            return *this;
        }

        constexpr span_iterator operator--(int)
        {
            auto ret = *this;
            --(*this);
            return ret;
        }

        constexpr span_iterator operator+(difference_type n) const
        {
            auto ret = *this;
            return ret += n;
        }

        friend constexpr span_iterator operator+(difference_type n, span_iterator const& rhs)
        {
            return rhs + n;
        }

        constexpr span_iterator& operator+=(difference_type n)
        {
            Expects((index_ + n) >= 0 && (index_ + n) <= span_->size());
            index_ += n;
            return *this;
        }

        constexpr span_iterator operator-(difference_type n) const
        {
            auto ret = *this;
            return ret -= n;
        }

        constexpr span_iterator& operator-=(difference_type n) { return *this += -n; }

        constexpr difference_type operator-(span_iterator rhs) const
        {
            Expects(span_ == rhs.span_);
            return index_ - rhs.index_;
        }

        constexpr reference operator[](difference_type n) const { return *(*this + n); }

        constexpr friend bool operator==(span_iterator lhs, span_iterator rhs) noexcept
        {
            return lhs.span_ == rhs.span_ && lhs.index_ == rhs.index_;
        }

        constexpr friend bool operator!=(span_iterator lhs, span_iterator rhs) noexcept
        {
            return !(lhs == rhs);
        }

        constexpr friend bool operator<(span_iterator lhs, span_iterator rhs) noexcept
        {
            return lhs.index_ < rhs.index_;
        }

        constexpr friend bool operator<=(span_iterator lhs, span_iterator rhs) noexcept
        {
            return !(rhs < lhs);
        }

        constexpr friend bool operator>(span_iterator lhs, span_iterator rhs) noexcept
        {
            return rhs < lhs;
        }

        constexpr friend bool operator>=(span_iterator lhs, span_iterator rhs) noexcept
        {
            return !(rhs > lhs);
        }

#ifdef _MSC_VER
        // MSVC++ iterator debugging support; allows STL algorithms in 15.8+
        // to unwrap span_iterator to a pointer type after a range check in STL
        // algorithm calls
        friend constexpr void _Verify_range(span_iterator lhs, span_iterator rhs) noexcept
        { // test that [lhs, rhs) forms a valid range inside an STL algorithm
            Expects(lhs.span_ == rhs.span_        // range spans have to match
                    && lhs.index_ <= rhs.index_); // range must not be transposed
        }

        constexpr void _Verify_offset(const difference_type n) const noexcept
        { // test that the iterator *this + n is a valid range in an STL
            // algorithm call
            Expects((index_ + n) >= 0 && (index_ + n) <= span_->size());
        }

        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        constexpr pointer _Unwrapped() const noexcept
        { // after seeking *this to a high water mark, or using one of the
            // _Verify_xxx functions above, unwrap this span_iterator to a raw
            // pointer
            return span_->data() + index_;
        }

        // Tell the STL that span_iterator should not be unwrapped if it can't
        // validate in advance, even in release / optimized builds:
#if defined(GSL_USE_STATIC_CONSTEXPR_WORKAROUND)
        static constexpr const bool _Unwrap_when_unverified = false;
#else
        static constexpr bool _Unwrap_when_unverified = false;
#endif
        GSL_SUPPRESS(con.3) // NO-FORMAT: attribute // TODO: false positive
        constexpr void _Seek_to(const pointer p) noexcept
        { // adjust the position of *this to previously verified location p
            // after _Unwrapped
            index_ = p - span_->data();
        }
#endif

    protected:
        const Span* span_ = nullptr;
        std::ptrdiff_t index_ = 0;
    };

    template <std::ptrdiff_t Ext>
    class extent_type
    {
    public:
        using index_type = std::ptrdiff_t;

        static_assert(Ext >= 0, "A fixed-size span must be >= 0 in size.");

        constexpr extent_type() noexcept {}

        template <index_type Other>
        constexpr extent_type(extent_type<Other> ext)
        {
            static_assert(Other == Ext || Other == dynamic_extent,
                          "Mismatch between fixed-size extent and size of initializing data.");
            Expects(ext.size() == Ext);
        }

        constexpr extent_type(index_type size) { Expects(size == Ext); }

        constexpr index_type size() const noexcept { return Ext; }
    };

    template <>
    class extent_type<dynamic_extent>
    {
    public:
        using index_type = std::ptrdiff_t;

        template <index_type Other>
        explicit constexpr extent_type(extent_type<Other> ext) : size_(ext.size())
        {}

        explicit constexpr extent_type(index_type size) : size_(size) { Expects(size >= 0); }

        constexpr index_type size() const noexcept { return size_; }

    private:
        index_type size_;
    };

    template <class ElementType, std::ptrdiff_t Extent, std::ptrdiff_t Offset, std::ptrdiff_t Count>
    struct calculate_subspan_type
    {
        using type = span<ElementType, Count != dynamic_extent
                                           ? Count
                                           : (Extent != dynamic_extent ? Extent - Offset : Extent)>;
    };
} // namespace details

// [span], class template span
template <class ElementType, std::ptrdiff_t Extent>
class span
{
public:
    // constants and types
    using element_type = ElementType;
    using value_type = std::remove_cv_t<ElementType>;
    using index_type = std::ptrdiff_t;
    using pointer = element_type*;
    using reference = element_type&;

    using iterator = details::span_iterator<span<ElementType, Extent>, false>;
    using const_iterator = details::span_iterator<span<ElementType, Extent>, true>;
    using reverse_iterator = std::reverse_iterator<iterator>;
    using const_reverse_iterator = std::reverse_iterator<const_iterator>;

    using size_type = index_type;

#if defined(GSL_USE_STATIC_CONSTEXPR_WORKAROUND)
    static constexpr const index_type extent{Extent};
#else
    static constexpr index_type extent{Extent};
#endif

    // [span.cons], span constructors, copy, assignment, and destructor
    template <bool Dependent = false,
              // "Dependent" is needed to make "std::enable_if_t<Dependent || Extent <= 0>" SFINAE,
              // since "std::enable_if_t<Extent <= 0>" is ill-formed when Extent is greater than 0.
              class = std::enable_if_t<(Dependent || Extent <= 0)>>
    constexpr span() noexcept : storage_(nullptr, details::extent_type<0>())
    {}

    constexpr span(pointer ptr, index_type count) : storage_(ptr, count) {}

    constexpr span(pointer firstElem, pointer lastElem)
        : storage_(firstElem, std::distance(firstElem, lastElem))
    {}

    template <std::size_t N>
    constexpr span(element_type (&arr)[N]) noexcept
        : storage_(KnownNotNull{std::addressof(arr[0])}, details::extent_type<N>())
    {}

    template <std::size_t N, class = std::enable_if_t<(N > 0)>>
    constexpr span(std::array<std::remove_const_t<element_type>, N>& arr) noexcept
        : storage_(KnownNotNull{arr.data()}, details::extent_type<N>())
    {
    }

    constexpr span(std::array<std::remove_const_t<element_type>, 0>&) noexcept
        : storage_(static_cast<pointer>(nullptr), details::extent_type<0>())
    {
    }

    template <std::size_t N, class = std::enable_if_t<(N > 0)>>
    constexpr span(const std::array<std::remove_const_t<element_type>, N>& arr) noexcept
        : storage_(KnownNotNull{arr.data()}, details::extent_type<N>())
    {
    }

    constexpr span(const std::array<std::remove_const_t<element_type>, 0>&) noexcept
        : storage_(static_cast<pointer>(nullptr), details::extent_type<0>())
    {
    }

    // NB: the SFINAE here uses .data() as a incomplete/imperfect proxy for the requirement
    // on Container to be a contiguous sequence container.
    template <class Container,
              class = std::enable_if_t<
                  !details::is_span<Container>::value && !details::is_std_array<Container>::value &&
                  std::is_convertible<typename Container::pointer, pointer>::value &&
                  std::is_convertible<typename Container::pointer,
                                      decltype(std::declval<Container>().data())>::value>>
    constexpr span(Container& cont) : span(cont.data(), narrow<index_type>(cont.size()))
    {}

    template <class Container,
              class = std::enable_if_t<
                  std::is_const<element_type>::value && !details::is_span<Container>::value &&
                  std::is_convertible<typename Container::pointer, pointer>::value &&
                  std::is_convertible<typename Container::pointer,
                                      decltype(std::declval<Container>().data())>::value>>
    constexpr span(const Container& cont) : span(cont.data(), narrow<index_type>(cont.size()))
    {}

    constexpr span(const span& other) noexcept = default;

    template <
        class OtherElementType, std::ptrdiff_t OtherExtent,
        class = std::enable_if_t<
            details::is_allowed_extent_conversion<OtherExtent, Extent>::value &&
            details::is_allowed_element_type_conversion<OtherElementType, element_type>::value>>
    constexpr span(const span<OtherElementType, OtherExtent>& other)
        : storage_(other.data(), details::extent_type<OtherExtent>(other.size()))
    {}

    ~span() noexcept = default;
    constexpr span& operator=(const span& other) noexcept = default;

    // [span.sub], span subviews
    template <std::ptrdiff_t Count>
    constexpr span<element_type, Count> first() const
    {
        Expects(Count >= 0 && Count <= size());
        return {data(), Count};
    }

    template <std::ptrdiff_t Count>
    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    constexpr span<element_type, Count> last() const
    {
        Expects(Count >= 0 && size() - Count >= 0);
        return {data() + (size() - Count), Count};
    }

    template <std::ptrdiff_t Offset, std::ptrdiff_t Count = dynamic_extent>
    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    constexpr auto subspan() const ->
        typename details::calculate_subspan_type<ElementType, Extent, Offset, Count>::type
    {
        Expects((Offset >= 0 && size() - Offset >= 0) &&
                (Count == dynamic_extent || (Count >= 0 && Offset + Count <= size())));

        return {data() + Offset, Count == dynamic_extent ? size() - Offset : Count};
    }

    constexpr span<element_type, dynamic_extent> first(index_type count) const
    {
        Expects(count >= 0 && count <= size());
        return {data(), count};
    }

    constexpr span<element_type, dynamic_extent> last(index_type count) const
    {
        return make_subspan(size() - count, dynamic_extent, subspan_selector<Extent>{});
    }

    constexpr span<element_type, dynamic_extent> subspan(index_type offset,
                                                         index_type count = dynamic_extent) const
    {
        return make_subspan(offset, count, subspan_selector<Extent>{});
    }

    // [span.obs], span observers
    constexpr index_type size() const noexcept { return storage_.size(); }
    constexpr index_type size_bytes() const noexcept
    {
        return size() * narrow_cast<index_type>(sizeof(element_type));
    }
    constexpr bool empty() const noexcept { return size() == 0; }

    // [span.elem], span element access
    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    constexpr reference operator[](index_type idx) const
    {
        Expects(CheckRange(idx, storage_.size()));
        return data()[idx];
    }

    constexpr reference at(index_type idx) const { return this->operator[](idx); }
    constexpr reference operator()(index_type idx) const { return this->operator[](idx); }
    constexpr pointer data() const noexcept { return storage_.data(); }

    // [span.iter], span iterator support
    constexpr iterator begin() const noexcept { return {this, 0}; }
    constexpr iterator end() const noexcept { return {this, size()}; }

    constexpr const_iterator cbegin() const noexcept { return {this, 0}; }
    constexpr const_iterator cend() const noexcept { return {this, size()}; }

    constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator{end()}; }
    constexpr reverse_iterator rend() const noexcept { return reverse_iterator{begin()}; }

    constexpr const_reverse_iterator crbegin() const noexcept
    {
        return const_reverse_iterator{cend()};
    }
    constexpr const_reverse_iterator crend() const noexcept
    {
        return const_reverse_iterator{cbegin()};
    }

#ifdef _MSC_VER
    // Tell MSVC how to unwrap spans in range-based-for
    constexpr pointer _Unchecked_begin() const noexcept { return data(); }
    constexpr pointer _Unchecked_end() const noexcept
    {
        GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
        return data() + size();
    }
#endif // _MSC_VER

private:
    static constexpr bool CheckRange(index_type idx, index_type size) noexcept
    {
        // Optimization:
        //
        // idx >= 0 && idx < size
        // =>
        // static_cast<size_t>(idx) < static_cast<size_t>(size)
        //
        // because size >=0 by span construction, and negative idx will
        // wrap around to a value always greater than size when casted.

        // check if we have enough space to wrap around
#if defined(__cpp_if_constexpr)
        if constexpr (sizeof(index_type) <= sizeof(size_t))
#else
        if (sizeof(index_type) <= sizeof(size_t))
#endif
        {
            return narrow_cast<size_t>(idx) < narrow_cast<size_t>(size);
        }
        else
        {
            return idx >= 0 && idx < size;
        }
    }

    // Needed to remove unnecessary null check in subspans
    struct KnownNotNull
    {
        pointer p;
    };

    // this implementation detail class lets us take advantage of the
    // empty base class optimization to pay for only storage of a single
    // pointer in the case of fixed-size spans
    template <class ExtentType>
    class storage_type : public ExtentType
    {
    public:
        // KnownNotNull parameter is needed to remove unnecessary null check
        // in subspans and constructors from arrays
        template <class OtherExtentType>
        constexpr storage_type(KnownNotNull data, OtherExtentType ext)
            : ExtentType(ext), data_(data.p)
        {
            Expects(ExtentType::size() >= 0);
        }

        template <class OtherExtentType>
        constexpr storage_type(pointer data, OtherExtentType ext) : ExtentType(ext), data_(data)
        {
            Expects(ExtentType::size() >= 0);
            Expects(data || ExtentType::size() == 0);
        }

        constexpr pointer data() const noexcept { return data_; }

    private:
        pointer data_;
    };

    storage_type<details::extent_type<Extent>> storage_;

    // The rest is needed to remove unnecessary null check
    // in subspans and constructors from arrays
    constexpr span(KnownNotNull ptr, index_type count) : storage_(ptr, count) {}

    template <std::ptrdiff_t CallerExtent>
    class subspan_selector
    {
    };

    template <std::ptrdiff_t CallerExtent>
    span<element_type, dynamic_extent> make_subspan(index_type offset, index_type count,
                                                    subspan_selector<CallerExtent>) const
    {
        const span<element_type, dynamic_extent> tmp(*this);
        return tmp.subspan(offset, count);
    }

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
    span<element_type, dynamic_extent> make_subspan(index_type offset, index_type count,
                                                    subspan_selector<dynamic_extent>) const
    {
        Expects(offset >= 0 && size() - offset >= 0);

        if (count == dynamic_extent) { return {KnownNotNull{data() + offset}, size() - offset}; }

        Expects(count >= 0 && size() - offset >= count);
        return {KnownNotNull{data() + offset}, count};
    }
};

#if defined(GSL_USE_STATIC_CONSTEXPR_WORKAROUND)
template <class ElementType, std::ptrdiff_t Extent>
constexpr const typename span<ElementType, Extent>::index_type span<ElementType, Extent>::extent;
#endif

// [span.comparison], span comparison operators
template <class ElementType, std::ptrdiff_t FirstExtent, std::ptrdiff_t SecondExtent>
constexpr bool operator==(span<ElementType, FirstExtent> l, span<ElementType, SecondExtent> r)
{
    return std::equal(l.begin(), l.end(), r.begin(), r.end());
}

template <class ElementType, std::ptrdiff_t Extent>
constexpr bool operator!=(span<ElementType, Extent> l, span<ElementType, Extent> r)
{
    return !(l == r);
}

template <class ElementType, std::ptrdiff_t Extent>
constexpr bool operator<(span<ElementType, Extent> l, span<ElementType, Extent> r)
{
    return std::lexicographical_compare(l.begin(), l.end(), r.begin(), r.end());
}

template <class ElementType, std::ptrdiff_t Extent>
constexpr bool operator<=(span<ElementType, Extent> l, span<ElementType, Extent> r)
{
    return !(l > r);
}

template <class ElementType, std::ptrdiff_t Extent>
constexpr bool operator>(span<ElementType, Extent> l, span<ElementType, Extent> r)
{
    return r < l;
}

template <class ElementType, std::ptrdiff_t Extent>
constexpr bool operator>=(span<ElementType, Extent> l, span<ElementType, Extent> r)
{
    return !(l < r);
}

namespace details
{
    // if we only supported compilers with good constexpr support then
    // this pair of classes could collapse down to a constexpr function

    // we should use a narrow_cast<> to go to std::size_t, but older compilers may not see it as
    // constexpr
    // and so will fail compilation of the template
    template <class ElementType, std::ptrdiff_t Extent>
    struct calculate_byte_size
        : std::integral_constant<std::ptrdiff_t,
                                 static_cast<std::ptrdiff_t>(sizeof(ElementType) *
                                                             static_cast<std::size_t>(Extent))>
    {
    };

    template <class ElementType>
    struct calculate_byte_size<ElementType, dynamic_extent>
        : std::integral_constant<std::ptrdiff_t, dynamic_extent>
    {
    };
} // namespace details

// [span.objectrep], views of object representation
template <class ElementType, std::ptrdiff_t Extent>
span<const byte, details::calculate_byte_size<ElementType, Extent>::value>
as_bytes(span<ElementType, Extent> s) noexcept
{
    GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
    return {reinterpret_cast<const byte*>(s.data()), s.size_bytes()};
}

template <class ElementType, std::ptrdiff_t Extent,
          class = std::enable_if_t<!std::is_const<ElementType>::value>>
span<byte, details::calculate_byte_size<ElementType, Extent>::value>
as_writeable_bytes(span<ElementType, Extent> s) noexcept
{
    GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
    return {reinterpret_cast<byte*>(s.data()), s.size_bytes()};
}

//
// make_span() - Utility functions for creating spans
//
template <class ElementType>
constexpr span<ElementType> make_span(ElementType* ptr,
                                      typename span<ElementType>::index_type count)
{
    return span<ElementType>(ptr, count);
}

template <class ElementType>
constexpr span<ElementType> make_span(ElementType* firstElem, ElementType* lastElem)
{
    return span<ElementType>(firstElem, lastElem);
}

template <class ElementType, std::size_t N>
constexpr span<ElementType, N> make_span(ElementType (&arr)[N]) noexcept
{
    return span<ElementType, N>(arr);
}

template <class Container>
constexpr span<typename Container::value_type> make_span(Container& cont)
{
    return span<typename Container::value_type>(cont);
}

template <class Container>
constexpr span<const typename Container::value_type> make_span(const Container& cont)
{
    return span<const typename Container::value_type>(cont);
}

template <class Ptr>
constexpr span<typename Ptr::element_type> make_span(Ptr& cont, std::ptrdiff_t count)
{
    return span<typename Ptr::element_type>(cont, count);
}

template <class Ptr>
constexpr span<typename Ptr::element_type> make_span(Ptr& cont)
{
    return span<typename Ptr::element_type>(cont);
}

// Specialization of gsl::at for span
template <class ElementType, std::ptrdiff_t Extent>
constexpr ElementType& at(span<ElementType, Extent> s, index i)
{
    // No bounds checking here because it is done in span::operator[] called below
    return s[i];
}

} // namespace gsl

#if defined(_MSC_VER) && !defined(__clang__)
#if _MSC_VER < 1910
#undef constexpr
#pragma pop_macro("constexpr")

#endif // _MSC_VER < 1910

#pragma warning(pop)
#endif // _MSC_VER

#if defined(__GNUC__) && __GNUC__ > 6
#pragma GCC diagnostic pop
#endif // __GNUC__ > 6

#endif // GSL_SPAN_H

D module-utils/gsl/string_span => module-utils/gsl/string_span +0 -722
@@ 1,722 0,0 @@
///////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
//
// This code is licensed under the MIT License (MIT).
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef GSL_STRING_SPAN_H
#define GSL_STRING_SPAN_H

#include <gsl/gsl_assert> // for Ensures, Expects
#include <gsl/gsl_util>   // for narrow_cast
#include <gsl/span>       // for operator!=, operator==, dynamic_extent
#include <gsl/pointers>   // for not_null

#include <algorithm> // for equal, lexicographical_compare
#include <array>     // for array
#include <cstddef>   // for ptrdiff_t, size_t, nullptr_t
#include <cstdint>   // for PTRDIFF_MAX
#include <cstring>
#include <string>      // for basic_string, allocator, char_traits
#include <type_traits> // for declval, is_convertible, enable_if_t, add_...

#if defined(_MSC_VER) && !defined(__clang__)
#pragma warning(push)

// Turn MSVC /analyze rules that generate too much noise. TODO: fix in the tool.
#pragma warning(disable : 26446) // TODO: bug in parser - attributes and templates
#pragma warning(disable : 26481) // TODO: suppress does not work inside templates sometimes

#if _MSC_VER < 1910
#pragma push_macro("constexpr")
#define constexpr /*constexpr*/

#endif // _MSC_VER < 1910
#endif // _MSC_VER

namespace gsl
{
//
// czstring and wzstring
//
// These are "tag" typedefs for C-style strings (i.e. null-terminated character arrays)
// that allow static analysis to help find bugs.
//
// There are no additional features/semantics that we can find a way to add inside the
// type system for these types that will not either incur significant runtime costs or
// (sometimes needlessly) break existing programs when introduced.
//

template <typename CharT, std::ptrdiff_t Extent = dynamic_extent>
using basic_zstring = CharT*;

template <std::ptrdiff_t Extent = dynamic_extent>
using czstring = basic_zstring<const char, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using cwzstring = basic_zstring<const wchar_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using cu16zstring = basic_zstring<const char16_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using cu32zstring = basic_zstring<const char32_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using zstring = basic_zstring<char, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using wzstring = basic_zstring<wchar_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using u16zstring = basic_zstring<char16_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using u32zstring = basic_zstring<char32_t, Extent>;

namespace details
{
    template <class CharT>
    std::ptrdiff_t string_length(const CharT* str, std::ptrdiff_t n)
    {
        if (str == nullptr || n <= 0) return 0;

        const span<const CharT> str_span{str, n};

        std::ptrdiff_t len = 0;
        while (len < n && str_span[len]) len++;

        return len;
    }
} // namespace details

//
// ensure_sentinel()
//
// Provides a way to obtain an span from a contiguous sequence
// that ends with a (non-inclusive) sentinel value.
//
// Will fail-fast if sentinel cannot be found before max elements are examined.
//
template <typename T, const T Sentinel>
span<T, dynamic_extent> ensure_sentinel(T* seq, std::ptrdiff_t max = PTRDIFF_MAX)
{
    Ensures(seq != nullptr);

    GSL_SUPPRESS(f.23) // NO-FORMAT: attribute // TODO: false positive // TODO: suppress does not work
    auto cur = seq;
    Ensures(cur != nullptr); // workaround for removing the warning

    GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute // TODO: suppress does not work
    while ((cur - seq) < max && *cur != Sentinel) ++cur;
    Ensures(*cur == Sentinel);
    return {seq, cur - seq};
}

//
// ensure_z - creates a span for a zero terminated strings.
// Will fail fast if a null-terminator cannot be found before
// the limit of size_type.
//
template <typename CharT>
span<CharT, dynamic_extent> ensure_z(CharT* const& sz, std::ptrdiff_t max = PTRDIFF_MAX)
{
    return ensure_sentinel<CharT, CharT(0)>(sz, max);
}

template <typename CharT, std::size_t N>
span<CharT, dynamic_extent> ensure_z(CharT (&sz)[N])
{
    return ensure_z(&sz[0], narrow_cast<std::ptrdiff_t>(N));
}

template <class Cont>
span<typename std::remove_pointer<typename Cont::pointer>::type, dynamic_extent>
ensure_z(Cont& cont)
{
    return ensure_z(cont.data(), narrow_cast<std::ptrdiff_t>(cont.size()));
}

template <typename CharT, std::ptrdiff_t>
class basic_string_span;

namespace details {
    template <typename T>
    struct is_basic_string_span_oracle : std::false_type
    {
    };

    template <typename CharT, std::ptrdiff_t Extent>
    struct is_basic_string_span_oracle<basic_string_span<CharT, Extent>> : std::true_type
    {
    };

    template <typename T>
    struct is_basic_string_span : is_basic_string_span_oracle<std::remove_cv_t<T>>
    {
    };
} // namespace details

//
// string_span and relatives
//
template <typename CharT, std::ptrdiff_t Extent = dynamic_extent>
class basic_string_span
{
public:
    using element_type = CharT;
    using value_type = std::remove_cv_t<element_type>;
    using pointer = std::add_pointer_t<element_type>;
    using reference = std::add_lvalue_reference_t<element_type>;
    using const_reference = std::add_lvalue_reference_t<std::add_const_t<element_type>>;
    using impl_type = span<element_type, Extent>;

    using index_type = typename impl_type::index_type;
    using iterator = typename impl_type::iterator;
    using const_iterator = typename impl_type::const_iterator;
    using reverse_iterator = typename impl_type::reverse_iterator;
    using const_reverse_iterator = typename impl_type::const_reverse_iterator;

    using size_type = index_type;

    // default (empty)
    constexpr basic_string_span() noexcept = default;

    // copy
    constexpr basic_string_span(const basic_string_span& other) noexcept = default;

    // assign
    constexpr basic_string_span& operator=(const basic_string_span& other) noexcept = default;

    constexpr basic_string_span(pointer ptr, index_type length) : span_(ptr, length) {}
    constexpr basic_string_span(pointer firstElem, pointer lastElem) : span_(firstElem, lastElem) {}

    // From static arrays - if 0-terminated, remove 0 from the view
    // All other containers allow 0s within the length, so we do not remove them
    template <std::size_t N>
    constexpr basic_string_span(element_type (&arr)[N]) : span_(remove_z(arr))
    {}

    template <std::size_t N, class ArrayElementType = std::remove_const_t<element_type>>
    constexpr basic_string_span(std::array<ArrayElementType, N>& arr) noexcept : span_(arr)
    {}

    template <std::size_t N, class ArrayElementType = std::remove_const_t<element_type>>
    constexpr basic_string_span(const std::array<ArrayElementType, N>& arr) noexcept : span_(arr)
    {}

    // Container signature should work for basic_string after C++17 version exists
    template <class Traits, class Allocator>
    // GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute // TODO: parser bug
    constexpr basic_string_span(std::basic_string<element_type, Traits, Allocator>& str)
        : span_(&str[0], narrow_cast<std::ptrdiff_t>(str.length()))
    {}

    template <class Traits, class Allocator>
    constexpr basic_string_span(const std::basic_string<element_type, Traits, Allocator>& str)
        : span_(&str[0], str.length())
    {}

    // from containers. Containers must have a pointer type and data() function signatures
    template <class Container,
              class = std::enable_if_t<
                  !details::is_basic_string_span<Container>::value &&
                  std::is_convertible<typename Container::pointer, pointer>::value &&
                  std::is_convertible<typename Container::pointer,
                                      decltype(std::declval<Container>().data())>::value>>
    constexpr basic_string_span(Container& cont) : span_(cont)
    {}

    template <class Container,
              class = std::enable_if_t<
                  !details::is_basic_string_span<Container>::value &&
                  std::is_convertible<typename Container::pointer, pointer>::value &&
                  std::is_convertible<typename Container::pointer,
                                      decltype(std::declval<Container>().data())>::value>>
    constexpr basic_string_span(const Container& cont) : span_(cont)
    {}

    // from string_span
    template <
        class OtherValueType, std::ptrdiff_t OtherExtent,
        class = std::enable_if_t<std::is_convertible<
            typename basic_string_span<OtherValueType, OtherExtent>::impl_type, impl_type>::value>>
    constexpr basic_string_span(basic_string_span<OtherValueType, OtherExtent> other)
        : span_(other.data(), other.length())
    {}

    template <index_type Count>
    constexpr basic_string_span<element_type, Count> first() const
    {
        return {span_.template first<Count>()};
    }

    constexpr basic_string_span<element_type, dynamic_extent> first(index_type count) const
    {
        return {span_.first(count)};
    }

    template <index_type Count>
    constexpr basic_string_span<element_type, Count> last() const
    {
        return {span_.template last<Count>()};
    }

    constexpr basic_string_span<element_type, dynamic_extent> last(index_type count) const
    {
        return {span_.last(count)};
    }

    template <index_type Offset, index_type Count>
    constexpr basic_string_span<element_type, Count> subspan() const
    {
        return {span_.template subspan<Offset, Count>()};
    }

    constexpr basic_string_span<element_type, dynamic_extent>
    subspan(index_type offset, index_type count = dynamic_extent) const
    {
        return {span_.subspan(offset, count)};
    }

    constexpr reference operator[](index_type idx) const { return span_[idx]; }
    constexpr reference operator()(index_type idx) const { return span_[idx]; }

    constexpr pointer data() const { return span_.data(); }

    constexpr index_type length() const noexcept { return span_.size(); }
    constexpr index_type size() const noexcept { return span_.size(); }
    constexpr index_type size_bytes() const noexcept { return span_.size_bytes(); }
    constexpr index_type length_bytes() const noexcept { return span_.length_bytes(); }
    constexpr bool empty() const noexcept { return size() == 0; }

    constexpr iterator begin() const noexcept { return span_.begin(); }
    constexpr iterator end() const noexcept { return span_.end(); }

    constexpr const_iterator cbegin() const noexcept { return span_.cbegin(); }
    constexpr const_iterator cend() const noexcept { return span_.cend(); }

    constexpr reverse_iterator rbegin() const noexcept { return span_.rbegin(); }
    constexpr reverse_iterator rend() const noexcept { return span_.rend(); }

    constexpr const_reverse_iterator crbegin() const noexcept { return span_.crbegin(); }
    constexpr const_reverse_iterator crend() const noexcept { return span_.crend(); }

private:
    static impl_type remove_z(pointer const& sz, std::ptrdiff_t max)
    {
        return {sz, details::string_length(sz, max)};
    }

    template <std::size_t N>
    static impl_type remove_z(element_type (&sz)[N])
    {
        return remove_z(&sz[0], narrow_cast<std::ptrdiff_t>(N));
    }

    impl_type span_;
};

template <std::ptrdiff_t Extent = dynamic_extent>
using string_span = basic_string_span<char, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using cstring_span = basic_string_span<const char, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using wstring_span = basic_string_span<wchar_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using cwstring_span = basic_string_span<const wchar_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using u16string_span = basic_string_span<char16_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using cu16string_span = basic_string_span<const char16_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using u32string_span = basic_string_span<char32_t, Extent>;

template <std::ptrdiff_t Extent = dynamic_extent>
using cu32string_span = basic_string_span<const char32_t, Extent>;

//
// to_string() allow (explicit) conversions from string_span to string
//

template <typename CharT, std::ptrdiff_t Extent>
std::basic_string<typename std::remove_const<CharT>::type>
to_string(basic_string_span<CharT, Extent> view)
{
    return {view.data(), narrow_cast<std::size_t>(view.length())};
}

template <typename CharT, typename Traits = typename std::char_traits<CharT>,
          typename Allocator = std::allocator<CharT>, typename gCharT, std::ptrdiff_t Extent>
std::basic_string<CharT, Traits, Allocator> to_basic_string(basic_string_span<gCharT, Extent> view)
{
    return {view.data(), narrow_cast<std::size_t>(view.length())};
}

template <class ElementType, std::ptrdiff_t Extent>
basic_string_span<const byte, details::calculate_byte_size<ElementType, Extent>::value>
as_bytes(basic_string_span<ElementType, Extent> s) noexcept
{
    GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
    return {reinterpret_cast<const byte*>(s.data()), s.size_bytes()};
}

template <class ElementType, std::ptrdiff_t Extent,
          class = std::enable_if_t<!std::is_const<ElementType>::value>>
basic_string_span<byte, details::calculate_byte_size<ElementType, Extent>::value>
as_writeable_bytes(basic_string_span<ElementType, Extent> s) noexcept
{
    GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
    return {reinterpret_cast<byte*>(s.data()), s.size_bytes()};
}

// zero-terminated string span, used to convert
// zero-terminated spans to legacy strings
template <typename CharT, std::ptrdiff_t Extent = dynamic_extent>
class basic_zstring_span {
public:
    using value_type = CharT;
    using const_value_type = std::add_const_t<CharT>;

    using pointer = std::add_pointer_t<value_type>;
    using const_pointer = std::add_pointer_t<const_value_type>;

    using zstring_type = basic_zstring<value_type, Extent>;
    using const_zstring_type = basic_zstring<const_value_type, Extent>;

    using impl_type = span<value_type, Extent>;
    using string_span_type = basic_string_span<value_type, Extent>;

    constexpr basic_zstring_span(impl_type s) : span_(s)
    {
        // expects a zero-terminated span
        Expects(s[s.size() - 1] == '\0');
    }

    // copy
    constexpr basic_zstring_span(const basic_zstring_span& other) = default;

    // move
    constexpr basic_zstring_span(basic_zstring_span&& other) = default;

    // assign
    constexpr basic_zstring_span& operator=(const basic_zstring_span& other) = default;

    // move assign
    constexpr basic_zstring_span& operator=(basic_zstring_span&& other) = default;

    constexpr bool empty() const noexcept { return span_.size() == 0; }

    constexpr string_span_type as_string_span() const noexcept
    {
        const auto sz = span_.size();
        return {span_.data(), sz > 1 ? sz - 1 : 0};
    }
    constexpr string_span_type ensure_z() const { return gsl::ensure_z(span_); }

    constexpr const_zstring_type assume_z() const noexcept { return span_.data(); }

private:
    impl_type span_;
};

template <std::ptrdiff_t Max = dynamic_extent>
using zstring_span = basic_zstring_span<char, Max>;

template <std::ptrdiff_t Max = dynamic_extent>
using wzstring_span = basic_zstring_span<wchar_t, Max>;

template <std::ptrdiff_t Max = dynamic_extent>
using u16zstring_span = basic_zstring_span<char16_t, Max>;

template <std::ptrdiff_t Max = dynamic_extent>
using u32zstring_span = basic_zstring_span<char32_t, Max>;

template <std::ptrdiff_t Max = dynamic_extent>
using czstring_span = basic_zstring_span<const char, Max>;

template <std::ptrdiff_t Max = dynamic_extent>
using cwzstring_span = basic_zstring_span<const wchar_t, Max>;

template <std::ptrdiff_t Max = dynamic_extent>
using cu16zstring_span = basic_zstring_span<const char16_t, Max>;

template <std::ptrdiff_t Max = dynamic_extent>
using cu32zstring_span = basic_zstring_span<const char32_t, Max>;

// operator ==
template <class CharT, std::ptrdiff_t Extent, class T,
          class = std::enable_if_t<
              details::is_basic_string_span<T>::value ||
              std::is_convertible<T, gsl::basic_string_span<std::add_const_t<CharT>>>::value>>
bool operator==(const gsl::basic_string_span<CharT, Extent>& one, const T& other)
{
    const gsl::basic_string_span<std::add_const_t<CharT>> tmp(other);
    return std::equal(one.begin(), one.end(), tmp.begin(), tmp.end());
}

template <class CharT, std::ptrdiff_t Extent, class T,
          class = std::enable_if_t<
              !details::is_basic_string_span<T>::value &&
              std::is_convertible<T, gsl::basic_string_span<std::add_const_t<CharT>>>::value>>
bool operator==(const T& one, const gsl::basic_string_span<CharT, Extent>& other)
{
    const gsl::basic_string_span<std::add_const_t<CharT>> tmp(one);
    return std::equal(tmp.begin(), tmp.end(), other.begin(), other.end());
}

// operator !=
template <typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
          typename = std::enable_if_t<std::is_convertible<
              T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value>>
bool operator!=(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    return !(one == other);
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename = std::enable_if_t<
        std::is_convertible<T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value &&
        !gsl::details::is_basic_string_span<T>::value>>
bool operator!=(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    return !(one == other);
}

// operator<
template <typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
          typename = std::enable_if_t<std::is_convertible<
              T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value>>
bool operator<(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    const gsl::basic_string_span<std::add_const_t<CharT>, Extent> tmp(other);
    return std::lexicographical_compare(one.begin(), one.end(), tmp.begin(), tmp.end());
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename = std::enable_if_t<
        std::is_convertible<T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value &&
        !gsl::details::is_basic_string_span<T>::value>>
bool operator<(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    gsl::basic_string_span<std::add_const_t<CharT>, Extent> tmp(one);
    return std::lexicographical_compare(tmp.begin(), tmp.end(), other.begin(), other.end());
}

#ifndef _MSC_VER

// VS treats temp and const containers as convertible to basic_string_span,
// so the cases below are already covered by the previous operators

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator<(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    gsl::basic_string_span<std::add_const_t<CharT>, Extent> tmp(other);
    return std::lexicographical_compare(one.begin(), one.end(), tmp.begin(), tmp.end());
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator<(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    gsl::basic_string_span<std::add_const_t<CharT>, Extent> tmp(one);
    return std::lexicographical_compare(tmp.begin(), tmp.end(), other.begin(), other.end());
}
#endif

// operator <=
template <typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
          typename = std::enable_if_t<std::is_convertible<
              T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value>>
bool operator<=(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    return !(other < one);
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename = std::enable_if_t<
        std::is_convertible<T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value &&
        !gsl::details::is_basic_string_span<T>::value>>
bool operator<=(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    return !(other < one);
}

#ifndef _MSC_VER

// VS treats temp and const containers as convertible to basic_string_span,
// so the cases below are already covered by the previous operators

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator<=(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    return !(other < one);
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator<=(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    return !(other < one);
}
#endif

// operator>
template <typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
          typename = std::enable_if_t<std::is_convertible<
              T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value>>
bool operator>(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    return other < one;
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename = std::enable_if_t<
        std::is_convertible<T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value &&
        !gsl::details::is_basic_string_span<T>::value>>
bool operator>(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    return other < one;
}

#ifndef _MSC_VER

// VS treats temp and const containers as convertible to basic_string_span,
// so the cases below are already covered by the previous operators

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator>(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    return other < one;
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator>(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    return other < one;
}
#endif

// operator >=
template <typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
          typename = std::enable_if_t<std::is_convertible<
              T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value>>
bool operator>=(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    return !(one < other);
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename = std::enable_if_t<
        std::is_convertible<T, gsl::basic_string_span<std::add_const_t<CharT>, Extent>>::value &&
        !gsl::details::is_basic_string_span<T>::value>>
bool operator>=(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    return !(one < other);
}

#ifndef _MSC_VER

// VS treats temp and const containers as convertible to basic_string_span,
// so the cases below are already covered by the previous operators

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator>=(gsl::basic_string_span<CharT, Extent> one, const T& other)
{
    return !(one < other);
}

template <
    typename CharT, std::ptrdiff_t Extent = gsl::dynamic_extent, typename T,
    typename DataType = typename T::value_type,
    typename = std::enable_if_t<
        !gsl::details::is_span<T>::value && !gsl::details::is_basic_string_span<T>::value &&
        std::is_convertible<DataType*, CharT*>::value &&
        std::is_same<std::decay_t<decltype(std::declval<T>().size(), *std::declval<T>().data())>,
                     DataType>::value>>
bool operator>=(const T& one, gsl::basic_string_span<CharT, Extent> other)
{
    return !(one < other);
}
#endif
} // namespace gsl

#if defined(_MSC_VER) && !defined(__clang__)
#pragma warning(pop)

#if _MSC_VER < 1910
#undef constexpr
#pragma pop_macro("constexpr")

#endif // _MSC_VER < 1910
#endif // _MSC_VER

#endif // GSL_STRING_SPAN_H

M module-utils/log/Logger.cpp => module-utils/log/Logger.cpp +1 -1
@@ 3,7 3,7 @@

#include "critical.hpp"
#include <fstream>
#include <gsl/gsl_util>
#include <gsl/util>
#include "LockGuard.hpp"
#include "Logger.hpp"
#include "macros.h"

M third-party/CMakeLists.txt => third-party/CMakeLists.txt +1 -0
@@ 11,3 11,4 @@ add_subdirectory(tinyexpr)
add_subdirectory(parallel-hashmap)
add_subdirectory(protobuf)
add_subdirectory(littlefs)
add_subdirectory(gsl)

A third-party/gsl => third-party/gsl +1 -0
@@ 0,0 1,1 @@
Subproject commit b26f6d5ec7b043f9d459c1dfdd6da4d930d4e9b4