Version 4.0.0 of Microsoft\u2019s implementation of the C++ Core Guidelines Support Library<\/a> (GSL) is now available for you to download on the releases page<\/a>. This release maintains the safety guarantees that we have always offered and adds improvements to various parts of the library.<\/p>\n\n\n\n isocpp\/CppCoreGuidelines#1680<\/a> removed All headers which previously contained a To more closely align Microsoft\u2019s GSL with the C++ Core Guidelines, The functions Note: The list of supported compilers\/toolsets has been updated with newer versions. More info on compiler support can be found in the README.md<\/a>.<\/p>\n\n\n\nWhat changed in this release?<\/h2>\n\n\n\n
gsl::string_span<\/code><\/a><\/li><gsl\/multi_span><\/code><\/a><\/li>gsl_<\/code> prefix<\/a><\/li>not_null<\/code><\/a><\/li>gsl::span<\/code> and std::span<\/code> now use the correct specialization of gsl::at<\/code><\/a><\/li>zstring<\/code> family no longer requires empty brackets to be used: issue#992<\/a>void foo(zstring<> str);<\/code> should now be void foo(zstring str);<\/code><\/li><\/ul><\/li>gsl::narrowing_error<\/code> now has a helpful what()<\/code> message<\/li>finally<\/code> and final_action<\/code> are now [[nodiscard]]<\/code><\/li>GSL_NO_IOSTREAMS<\/code> flag: #953<\/a><\/li>Deprecation of
gsl::string_span<\/code><\/h2>\n\n\n\nstring_span<\/code> from the C++ Core Guidelines. The recommendation is to use std::string_view<\/code>, std::span<char><\/code> or gsl::span<char><\/code> instead. To more closely align Microsoft\u2019s GSL with the C++ Core Guidelines, we deprecated our implementation of string_span<\/code> and zstring_span<\/code>, including basic_string_span<\/code>, basic_zstring_span<\/code>, and all related types. For the time being, we will continue to provide the <gsl\/string_span><\/code> header, but it will not be actively worked on or maintained. A table of all supported and unsupported types\/features can be found in the README.md<\/a>.<\/p>\n\n\n\nRemoval of
<gsl\/multi_span><\/code><\/h2>\n\n\n\nmulti_span<\/code>, strided_span<\/code>, and everything else in <gsl\/multi_span><\/code> were deprecated over a year ago in GSL 3.0.0<\/a>, and it is time for them and their associated tests to be removed from the library.<\/p>\n\n\n\nHeader files dropped the
gsl_<\/code> prefix<\/h2>\n\n\n\ngsl_<\/code> prefix in their name have had this prefix removed. For example, <gsl\/gsl_algorithm><\/code> is now <gsl\/algorithm><\/code>. The gsl_<\/code> prefixed files still exist and pass through to the updated files, but will be removed in a future release.<\/p>\n\n\n\nChanges to
not_null<\/code><\/h2>\n\n\n\ngsl::not_null<\/code> now accepts only types which are comparable<\/em> to nullptr<\/code>. Previously, it accepted only types which are assignable<\/em> from nullptr<\/code>, but this was stricter than what was intended by the Core Guidelines<\/a>.<\/p>\n\n\n\nmake_not_null<\/code> and make_strict_not_null<\/code>, and the not_null<\/code> comparison operators, are now all noexcept<\/code>.<\/p>\n\n\n\ngsl::span<\/code> and std::span<\/code> now use the correct specialization of gsl::at<\/code><\/h2>\n\n\n\ngsl::span<\/code> and std::span<\/code> now have their own separate specializations of gsl::at<\/code>, to ensure consistent behavior between the two versions of span. Both overloads are included when importing <gsl\/span><\/code>. The std::span<\/code> overload can be separately included from <gsl\/util><\/code>.<\/p>\n\n\n\nGSL will work in environments where exceptions are disabled, with some caveats<\/h2>\n\n\n\n
gsl::narrow<\/code> is the only part of the library which may throw exceptions and has been moved into its own header <gsl\/narrow><\/code>. This header is included in <gsl\/gsl><\/code> only if exceptions are enabled. This allows users of the library who are working in environments without exceptions to use all of the other components of the library.<\/p>\n\n\n\ngsl::narrow_cast<\/code> is still in <gsl\/util><\/code>, since it does not throw exceptions.<\/p>\n\n\n\nUpdated compiler support<\/h2>\n\n\n\n