boost/hana/config.hpp
/*! @file Defines configuration macros used throughout the library. Copyright Louis Dionne 2013-2022 Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) */ #ifndef BOOST_HANA_CONFIG_HPP #define BOOST_HANA_CONFIG_HPP #include <boost/hana/version.hpp> ////////////////////////////////////////////////////////////////////////////// // Detect the compiler ////////////////////////////////////////////////////////////////////////////// #if defined(_MSC_VER) && !defined(__clang__) // MSVC // This must be checked first, because otherwise it produces a fatal // error due to unrecognized #warning directives used below. # if _MSC_VER < 1915 # pragma message("Warning: the native Microsoft compiler is not supported due to lack of proper C++14 support.") # else // 1. Active issues // Multiple copy/move ctors # define BOOST_HANA_WORKAROUND_MSVC_MULTIPLECTOR_106654 // 2. Issues fixed in the development branch of MSVC // Forward declaration of class template member function returning decltype(auto) # define BOOST_HANA_WORKAROUND_MSVC_DECLTYPEAUTO_RETURNTYPE_662735 // 3. Issues fixed conditionally // Requires __declspec(empty_bases) // Empty base optimization # define BOOST_HANA_WORKAROUND_MSVC_EMPTYBASE // Requires /experimental:preprocessor // Variadic macro expansion # if !defined(_MSVC_TRADITIONAL) || _MSVC_TRADITIONAL # define BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033 # endif # endif #elif defined(__clang__) && defined(_MSC_VER) // Clang-cl (Clang for Windows) # define BOOST_HANA_CONFIG_CLANG BOOST_HANA_CONFIG_VERSION( \ __clang_major__, __clang_minor__, __clang_patchlevel__) #elif defined(__clang__) && defined(__apple_build_version__) // Apple's Clang # if __apple_build_version__ >= 6020049 # define BOOST_HANA_CONFIG_CLANG BOOST_HANA_CONFIG_VERSION(3, 6, 0) # endif #elif defined(__clang__) // genuine Clang # define BOOST_HANA_CONFIG_CLANG BOOST_HANA_CONFIG_VERSION( \ __clang_major__, __clang_minor__, __clang_patchlevel__) #elif defined(__GNUC__) // GCC # define BOOST_HANA_CONFIG_GCC BOOST_HANA_CONFIG_VERSION( \ __GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__) #endif ////////////////////////////////////////////////////////////////////////////// // Check the compiler for general C++14 capabilities ////////////////////////////////////////////////////////////////////////////// #if (__cplusplus < 201400) # if defined(_MSC_VER) # if _MSC_VER < 1915 # pragma message("Warning: Your compiler doesn't provide C++14 or higher capabilities. Try adding the compiler flag '-std=c++14' or '-std=c++1y'.") # endif # else # warning "Your compiler doesn't provide C++14 or higher capabilities. Try adding the compiler flag '-std=c++14' or '-std=c++1y'." # endif #endif ////////////////////////////////////////////////////////////////////////////// // Caveats and other compiler-dependent options ////////////////////////////////////////////////////////////////////////////// // `BOOST_HANA_CONFIG_HAS_CONSTEXPR_LAMBDA` enables some constructs requiring // `constexpr` lambdas, which are in the language starting with C++17. // // Always disabled for now because Clang only has partial support for them // (captureless lambdas only). #if defined(__cplusplus) && __cplusplus > 201402L # define BOOST_HANA_CONSTEXPR_STATELESS_LAMBDA constexpr // # define BOOST_HANA_CONFIG_HAS_CONSTEXPR_LAMBDA #else # define BOOST_HANA_CONSTEXPR_STATELESS_LAMBDA /* nothing */ #endif // `BOOST_HANA_CONSTEXPR_LAMBDA` expands to `constexpr` if constexpr lambdas // are supported and to nothing otherwise. #if defined(BOOST_HANA_CONFIG_HAS_CONSTEXPR_LAMBDA) # define BOOST_HANA_CONSTEXPR_LAMBDA constexpr #else # define BOOST_HANA_CONSTEXPR_LAMBDA /* nothing */ #endif // `BOOST_HANA_INLINE_VARIABLE` expands to `inline` when C++17 inline variables // are supported, and to nothing otherwise. This allows marking global variables // defined in a header as `inline` to avoid potential ODR violations. #if defined(__cplusplus) && __cplusplus > 201402L # define BOOST_HANA_INLINE_VARIABLE inline #else # define BOOST_HANA_INLINE_VARIABLE /* nothing */ #endif ////////////////////////////////////////////////////////////////////////////// // Library features and options that can be tweaked by users ////////////////////////////////////////////////////////////////////////////// #if defined(BOOST_HANA_DOXYGEN_INVOKED) || \ (defined(NDEBUG) && !defined(BOOST_HANA_CONFIG_DISABLE_ASSERTIONS)) //! @ingroup group-config //! Disables the `BOOST_HANA_*_ASSERT` macro & friends. //! //! When this macro is defined, the `BOOST_HANA_*_ASSERT` macro & friends //! are disabled, i.e. they expand to nothing. //! //! This macro is defined automatically when `NDEBUG` is defined. It can //! also be defined by users before including this header or defined on //! the command line. # define BOOST_HANA_CONFIG_DISABLE_ASSERTIONS #endif #if defined(BOOST_HANA_DOXYGEN_INVOKED) //! @ingroup group-config //! Disables concept checks in interface methods. //! //! When this macro is not defined (the default), tag-dispatched methods //! will make sure the arguments they are passed are models of the proper //! concept(s). This can be very helpful in catching programming errors, //! but it is also slightly less compile-time efficient. You should //! probably always leave the checks enabled (and hence never define this //! macro), except perhaps in translation units that are compiled very //! often but whose code using Hana is modified very rarely. # define BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS #endif #if defined(BOOST_HANA_DOXYGEN_INVOKED) //! @ingroup group-config //! Enables usage of the "string literal operator template" GNU extension. //! //! That operator is not part of the language yet, but it is supported by //! both Clang and GCC. This operator allows Hana to provide the nice `_s` //! user-defined literal for creating compile-time strings. //! //! When this macro is not defined, the GNU extension will be not used //! by Hana. Because this is a non-standard extension, the macro is not //! defined by default. # define BOOST_HANA_CONFIG_ENABLE_STRING_UDL #endif #if defined(BOOST_HANA_DOXYGEN_INVOKED) //! @ingroup group-config //! Enables additional assertions and sanity checks to be done by Hana. //! //! When this macro is defined (it is __not defined__ by default), //! additional sanity checks may be done by Hana. These checks may //! be costly to perform, either in terms of compilation time or in //! terms of execution time. These checks may help debugging an //! application during its initial development, but they should not //! be enabled as part of the normal configuration. # define BOOST_HANA_CONFIG_ENABLE_DEBUG_MODE #endif #endif // !BOOST_HANA_CONFIG_HPP