#ifndef RBIMPL_CONSTANT_P_H /*-*-C++-*-vi:se ft=cpp:*/ #define RBIMPL_CONSTANT_P_H /** * @file * @author Ruby developers * @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 `RBIMPL` or `rbimpl` 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 Defines #RBIMPL_CONSTANT_P. * * Note that __builtin_constant_p can be applicable inside of inline functions, * according to GCC manual. Clang lacks that feature, though. * * @see https://bugs.llvm.org/show_bug.cgi?id=4898 * @see https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html */ #include "ruby/internal/has/builtin.h" #if RBIMPL_HAS_BUILTIN(__builtin_constant_p) # define RBIMPL_CONSTANT_P(expr) __builtin_constant_p(expr) #else # define RBIMPL_CONSTANT_P(expr) 0 #endif #endif /* RBIMPL_CONSTANT_P_H */