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__ */