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ruby--ruby/include/ruby/impl/attr/const.h

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#ifndef RBIMPL_ATTR_CONST_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ATTR_CONST_H
/**
* @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 `RBIMPL` 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 Defines #RBIMPL_ATTR_CONST.
*/
#include "ruby/impl/compiler_since.h"
#include "ruby/impl/has/attribute.h"
#include "ruby/impl/has/declspec_attribute.h"
/** Wraps (or simulates) `__attribute__((const))` */
#if RBIMPL_HAS_ATTRIBUTE(const)
# define RBIMPL_ATTR_CONST() __attribute__((__const__))
#elif RBIMPL_HAS_DECLSPEC_ATTRIBUTE(noalias)
# /* If a function can be a const, that is also a noalias. */
# define RBIMPL_ATTR_CONST() __declspec(noalias)
#elif RBIMPL_COMPILER_SINCE(SunPro, 5, 10, 0)
# define RBIMPL_ATTR_CONST() _Pragma("no_side_effect")
#else
# define RBIMPL_ATTR_CONST() /* void */
#endif
/** Enables #RBIMPL_ATTR_CONST iff. #RUBY_NDEBUG. */
#if RUBY_NDEBUG
# define RBIMPL_ATTR_CONST_ON_NDEBUG() RBIMPL_ATTR_CONST()
#else
# define RBIMPL_ATTR_CONST_ON_NDEBUG() /* void */
#endif
#endif /* RBIMPL_ATTR_CONST_H */