1/* GLIB - Library of useful routines for C programming
2 * Copyright (C) 2021 Iain Lane, Xavier Claessens
3 *
4 * SPDX-License-Identifier: LGPL-2.1-or-later
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20#ifndef __GLIB_TYPEOF_H__
21#define __GLIB_TYPEOF_H__
22
23#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
24#error "Only <glib.h> can be included directly."
25#endif
26
27#include <glib/gversionmacros.h>
28
29/*
30 * We can only use __typeof__ on GCC >= 4.8, and not when compiling C++. Since
31 * __typeof__ is used in a few places in GLib, provide a pre-processor symbol
32 * to factor the check out from callers.
33 *
34 * This symbol is private.
35 */
36#undef glib_typeof
37#if !G_CXX_STD_CHECK_VERSION (11) && \
38 (G_GNUC_CHECK_VERSION(4, 8) || defined(__clang__))
39#define glib_typeof(t) __typeof__ (t)
40#elif G_CXX_STD_CHECK_VERSION (11) && \
41 GLIB_VERSION_MIN_REQUIRED >= GLIB_VERSION_2_68
42/* C++11 decltype() is close enough for our usage */
43#include <type_traits>
44#define glib_typeof(t) typename std::remove_reference<decltype (t)>::type
45#endif
46
47#endif /* __GLIB_TYPEOF_H__ */
48