#ifndef RBIMPL_ATTR_MAYBE_UNUSED_H /*-*-C++-*-vi:se ft=cpp:*/ #define RBIMPL_ATTR_MAYBE_UNUSED_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_ATTR_MAYBE_UNUSED. */ #include "ruby/internal/has/attribute.h" #include "ruby/internal/has/c_attribute.h" #include "ruby/internal/has/cpp_attribute.h" /** Wraps (or simulates) `[[maybe_unused]]` */ #if RBIMPL_HAS_CPP_ATTRIBUTE(maybe_unused) # define RBIMPL_ATTR_MAYBE_UNUSED() [[maybe_unused]] #elif RBIMPL_HAS_C_ATTRIBUTE(maybe_unused) # define RBIMPL_ATTR_MAYBE_UNUSED() [[maybe_unused]] #elif RBIMPL_HAS_ATTRIBUTE(unused) # define RBIMPL_ATTR_MAYBE_UNUSED() __attribute__((__unused__)) #else # define RBIMPL_ATTR_MAYBE_UNUSED() /* void */ #endif #endif /* RBIMPL_ATTR_MAYBE_UNUSED */