glib2.0/glib/glib-typeof.h

48 lines
1.7 KiB
C++

/* GLIB - Library of useful routines for C programming
* Copyright (C) 2021 Iain Lane, Xavier Claessens
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __GLIB_TYPEOF_H__
#define __GLIB_TYPEOF_H__
#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
#error "Only <glib.h> can be included directly."
#endif
#include <glib/gversionmacros.h>
/*
* We can only use __typeof__ on GCC >= 4.8, and not when compiling C++. Since
* __typeof__ is used in a few places in GLib, provide a pre-processor symbol
* to factor the check out from callers.
*
* This symbol is private.
*/
#undef glib_typeof
#if !G_CXX_STD_CHECK_VERSION (11) && \
(G_GNUC_CHECK_VERSION(4, 8) || defined(__clang__))
#define glib_typeof(t) __typeof__ (t)
#elif G_CXX_STD_CHECK_VERSION (11) && \
GLIB_VERSION_MIN_REQUIRED >= GLIB_VERSION_2_68
/* C++11 decltype() is close enough for our usage */
#include <type_traits>
#define glib_typeof(t) typename std::remove_reference<decltype (t)>::type
#endif
#endif /* __GLIB_TYPEOF_H__ */