Current File : //opt/alt/ruby32/include/ruby/internal/attr/nodiscard.h
#ifndef RBIMPL_ATTR_NODISCARD_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ATTR_NODISCARD_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 `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_ATTR_NODISCARD.
*/
#include "ruby/internal/has/attribute.h"
#include "ruby/internal/has/c_attribute.h"
#include "ruby/internal/has/cpp_attribute.h"
/**
* Wraps (or simulates) `[[nodiscard]]`. In C++ (at least since C++20) a
* nodiscard attribute can have a message why the result shall not be ignored.
* However GCC attribute and SAL annotation cannot take them.
*/
#if RBIMPL_HAS_CPP_ATTRIBUTE(nodiscard)
# define RBIMPL_ATTR_NODISCARD() [[nodiscard]]
#elif RBIMPL_HAS_C_ATTRIBUTE(nodiscard)
# define RBIMPL_ATTR_NODISCARD() [[nodiscard]]
#elif RBIMPL_HAS_ATTRIBUTE(warn_unused_result)
# define RBIMPL_ATTR_NODISCARD() __attribute__((__warn_unused_result__))
#elif defined(_Check_return_)
# /* Take SAL definition. */
# define RBIMPL_ATTR_NODISCARD() _Check_return_
#else
# define RBIMPL_ATTR_NODISCARD() /* void */
#endif
#endif /* RBIMPL_ATTR_NODISCARD_H */