diff options
Diffstat (limited to 'include/ruby/3/attr/constexpr.h')
-rw-r--r-- | include/ruby/3/attr/constexpr.h | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/include/ruby/3/attr/constexpr.h b/include/ruby/3/attr/constexpr.h new file mode 100644 index 0000000000..5c09bced49 --- /dev/null +++ b/include/ruby/3/attr/constexpr.h @@ -0,0 +1,91 @@ +/** \noop-*-C++-*-vi:ft=cpp + * @file + * @author Ruby developers <ruby-core@ruby-lang.org> + * @copyright This file is a part of the programming language Ruby. + * Permission is hereby granted, to either redistribute and/or + * modify this file, provided that the conditions mentioned in the + * file COPYING are met. Consult the file for details. + * @warning Symbols prefixed with either `RUBY3` or `ruby3` are + * implementation details. Don't take them as canon. They could + * rapidly appear then vanish. The name (path) of this header file + * is also an implementation detail. Do not expect it to persist + * at the place it is now. Developers are free to move it anywhere + * anytime at will. + * @note To ruby-core: remember that this header can be possibly + * recursively included from extension libraries written in C++. + * Do not expect for instance `__VA_ARGS__` is always available. + * We assume C99 for ruby itself but we don't assume languages of + * extension libraries. They could be written in C++98. + * @brief #RUBY3_ATTR_CONSTEXPR. + */ +#include "ruby/3/has/feature.h" +#include "ruby/3/compiler_is.h" +#include "ruby/3/token_paste.h" + +/** @cond INTERNAL_MACRO*/ +#if defined(RUBY3_ATTR_CONSTEXPR) +# /* Take that. */ + +#elif ! defined(__cplusplus) +# /* Makes no sense. */ +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 0 +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 0 + +#elif defined(__cpp_constexpr) +# /* https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations */ +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 (__cpp_constexpr >= 200704L) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 (__cpp_constexpr >= 201304L) + +#elif RUBY3_COMPILER_SINCE(MSVC, 19, 0, 0) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 RUBY3_COMPILER_SINCE(MSVC, 19, 00, 00) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 RUBY3_COMPILER_SINCE(MSVC, 19, 11, 00) + +#elif RUBY3_COMPILER_SINCE(SunPro, 5, 13, 0) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 (__cplusplus >= 201103L) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 (__cplusplus >= 201402L) + +#elif RUBY3_COMPILER_SINCE(GCC, 4, 9, 0) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 (__cplusplus >= 201103L) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 (__cplusplus >= 201402L) + +#elif RUBY3_HAS_FEATURE(cxx_relaxed_constexpr) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 1 +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 1 + +#elif RUBY3_HAS_FEATURE(cxx_constexpr) +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 1 +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 0 + +#else +# /* :FIXME: icpc must have constexpr but don't know how to detect. */ +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX11 0 +# define RUBY3_HAS_ATTR_CONSTEXPR_CXX14 0 +#endif +/** @endcond */ + +/** Wraps (or simulates) C++11 `constexpr`. */ +#if defined(RUBY3_ATTR_CONSTEXPR) +# /* Take that. */ + +#elif RUBY3_HAS_ATTR_CONSTEXPR_CXX14 +# define RUBY3_ATTR_CONSTEXPR(_) constexpr + +#elif RUBY3_HAS_ATTR_CONSTEXPR_CXX11 +# define RUBY3_ATTR_CONSTEXPR(_) RUBY3_TOKEN_PASTE(RUBY3_ATTR_CONSTEXPR_, _) +# define RUBY3_ATTR_CONSTEXPR_CXX11 constexpr +# define RUBY3_ATTR_CONSTEXPR_CXX14 /* void */ + +#else +# define RUBY3_ATTR_CONSTEXPR(_) /* void */ +#endif + +/** Enables #RUBY3_ATTR_CONSTEXPR iff. #RUBY_NDEBUG. */ +#if defined(RUBY3_ATTR_CONSTEXPR_ON_NDEBUG) +# /* Take that. */ + +#elif RUBY_NDEBUG +# define RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(_) RUBY3_ATTR_CONSTEXPR(_) + +#else +# define RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(_) /* void */ +#endif |