v0.43.0

Additions:

not_null<> now supports function pointers and nullable function objects such as std::function<> and (for C++11 and newer) defines a conditionally enabled forwarding operator() to permit function-call syntax (#353, thanks to @n0F4x)
not_null<> now supports implicit construction from non-nullable arguments such as function objects and functions (#353)
Add is_nullable<> trait (#353, thanks to @BenFrantzDale)
Add tentative C++26 detection macro gsl_CPP26_OR_GREATER, CONSTEXPR_26 language feature, and gsl_constexpr26 keyword macro (61b8d1b72f6fb59fdcc86a9af8d3a005453ab877, 150c418e08d8db60f7ea93c13f9bd26af744f4b0)
For C++20 and newer, define operator<=> for not_null<> in C++20 (613a9ff8d8ec8dbab151dd4a9c82d45ebfa51a31)
For C++20 and newer, add gsl_NO_UNIQUE_ADDRESS which uses MSVC's ABI-breaking [[msvc::no_unique_address]] attribute if necessary (315c93569ac6539fb0f322a2441dfdac1c1aa156, a45222fb8f791def3d7e9a43fe69222ec5299952, 991aee66c31cb755559a8e9d36b6cc2693d183e2)

Changes:

Add feature macro gsl_FEATURE_STRING_SPAN, defaulting to 0 for version-1 defaults, to control the availability of string spans, which are no longer part of the GSL specification and have been deprecated for a while (2117b41f45c0d921e36996ee9f919475dd5bfffd)
Add feature macro gsl_FEATURE_BYTE, defaulting to 0 for version-1 defaults, to control the availability of byte, which has been superseded by std::byte in C++17 (dd3251e95144e7794163b6b31dc056f0992e6489)
If gsl_FEATURE_STRING_SPAN=0, we now avoid pulling in standard library header files <ios> and <string> (2117b41f45c0d921e36996ee9f919475dd5bfffd)
In version-1 mode, default to gsl_CONFIG_CONTRACT_VIOLATION_ASSERTS rather than gsl_CONFIG_CONTRACT_VIOLATION_TERMINATES, which is more convenient in practice (4e24de09ae3642fe71b99a3789180e6763b0a2b4)
gsl_FEATURE_WITH_CONTAINER_TO_STD now defaults to 0 with version-1 defaults (#353)
Remove unsupported CUDA toolkits and older GCC versions no longer available through Azure Pipelines (#353)

Fixes:

Add [[maybe_unused]] annotations to macro-generated function definitions to avoid Clang warnings about unused functions in anonymous namespaces (30e1390c1020172cee9c23e0a71f135b0e658abc)

Additions:

not_null<> now supports function pointers and nullable function objects such as std::function<> and (for C++11 and newer) defines a conditionally enabled forwarding operator() to permit function-call syntax (#353, thanks to @n0F4x)
not_null<> now supports implicit construction from non-nullable arguments such as function objects and functions (#353)
Add is_nullable<> trait (#353, thanks to @BenFrantzDale)
Add tentative C++26 detection macro gsl_CPP26_OR_GREATER, CONSTEXPR_26 language feature, and gsl_constexpr26 keyword macro (61b8d1b72f6fb59fdcc86a9af8d3a005453ab877, 150c418e08d8db60f7ea93c13f9bd26af744f4b0)
For C++20 and newer, define operator<=> for not_null<> in C++20 (613a9ff8d8ec8dbab151dd4a9c82d45ebfa51a31)
For C++20 and newer, add gsl_NO_UNIQUE_ADDRESS which uses MSVC's ABI-breaking [[msvc::no_unique_address]] attribute if necessary (315c93569ac6539fb0f322a2441dfdac1c1aa156, a45222fb8f791def3d7e9a43fe69222ec5299952, 991aee66c31cb755559a8e9d36b6cc2693d183e2)

Changes:

Add feature macro gsl_FEATURE_STRING_SPAN, defaulting to 0 for version-1 defaults, to control the availability of string spans, which are no longer part of the GSL specification and have been deprecated for a while (2117b41f45c0d921e36996ee9f919475dd5bfffd)
Add feature macro gsl_FEATURE_BYTE, defaulting to 0 for version-1 defaults, to control the availability of byte, which has been superseded by std::byte in C++17 (dd3251e95144e7794163b6b31dc056f0992e6489)
If gsl_FEATURE_STRING_SPAN=0, we now avoid pulling in standard library header files <ios> and <string> (2117b41f45c0d921e36996ee9f919475dd5bfffd)
In version-1 mode, default to gsl_CONFIG_CONTRACT_VIOLATION_ASSERTS rather than gsl_CONFIG_CONTRACT_VIOLATION_TERMINATES, which is more convenient in practice (4e24de09ae3642fe71b99a3789180e6763b0a2b4)
gsl_FEATURE_WITH_CONTAINER_TO_STD now defaults to 0 with version-1 defaults (#353)
Remove unsupported CUDA toolkits and older GCC versions no longer available through Azure Pipelines (#353)

Fixes:

Add [[maybe_unused]] annotations to macro-generated function definitions to avoid Clang warnings about unused functions in anonymous namespaces (30e1390c1020172cee9c23e0a71f135b0e658abc)

gsl-lite