1  // Concept-checking control -*- C++ -*-
       2  
       3  // Copyright (C) 2001-2023 Free Software Foundation, Inc.
       4  //
       5  // This file is part of the GNU ISO C++ Library.  This library is free
       6  // software; you can redistribute it and/or modify it under the
       7  // terms of the GNU General Public License as published by the
       8  // Free Software Foundation; either version 3, or (at your option)
       9  // 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
      14  // GNU General Public License for more details.
      15  
      16  // Under Section 7 of GPL version 3, you are granted additional
      17  // permissions described in the GCC Runtime Library Exception, version
      18  // 3.1, as published by the Free Software Foundation.
      19  
      20  // You should have received a copy of the GNU General Public License and
      21  // a copy of the GCC Runtime Library Exception along with this program;
      22  // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23  // <http://www.gnu.org/licenses/>.
      24  
      25  /** @file bits/concept_check.h
      26   *  This is an internal header file, included by other library headers.
      27   *  Do not attempt to use it directly. @headername{iterator}
      28   */
      29  
      30  #ifndef _CONCEPT_CHECK_H
      31  #define _CONCEPT_CHECK_H 1
      32  
      33  #pragma GCC system_header
      34  
      35  #include <bits/c++config.h>
      36  
      37  // All places in libstdc++-v3 where these are used, or /might/ be used, or
      38  // don't need to be used, or perhaps /should/ be used, are commented with
      39  // "concept requirements" (and maybe some more text).  So grep like crazy
      40  // if you're looking for additional places to use these.
      41  
      42  // Concept-checking code is off by default unless users turn it on via
      43  // configure options or editing c++config.h.
      44  // It is not supported for freestanding implementations.
      45  
      46  #if !defined(_GLIBCXX_CONCEPT_CHECKS)
      47  
      48  #define __glibcxx_function_requires(...)
      49  #define __glibcxx_class_requires(_a,_b)
      50  #define __glibcxx_class_requires2(_a,_b,_c)
      51  #define __glibcxx_class_requires3(_a,_b,_c,_d)
      52  #define __glibcxx_class_requires4(_a,_b,_c,_d,_e)
      53  
      54  #else // the checks are on
      55  
      56  #include <bits/boost_concept_check.h>
      57  
      58  // Note that the obvious and elegant approach of
      59  //
      60  //#define glibcxx_function_requires(C) debug::function_requires< debug::C >()
      61  //
      62  // won't work due to concept templates with more than one parameter, e.g.,
      63  // BinaryPredicateConcept.  The preprocessor tries to split things up on
      64  // the commas in the template argument list.  We can't use an inner pair of
      65  // parenthesis to hide the commas, because "debug::(Temp<Foo,Bar>)" isn't
      66  // a valid instantiation pattern.  Thus, we steal a feature from C99.
      67  
      68  #define __glibcxx_function_requires(...)                                 \
      69              __gnu_cxx::__function_requires< __gnu_cxx::__VA_ARGS__ >();
      70  #define __glibcxx_class_requires(_a,_C)                                  \
      71              _GLIBCXX_CLASS_REQUIRES(_a, __gnu_cxx, _C);
      72  #define __glibcxx_class_requires2(_a,_b,_C)                              \
      73              _GLIBCXX_CLASS_REQUIRES2(_a, _b, __gnu_cxx, _C);
      74  #define __glibcxx_class_requires3(_a,_b,_c,_C)                           \
      75              _GLIBCXX_CLASS_REQUIRES3(_a, _b, _c, __gnu_cxx, _C);
      76  #define __glibcxx_class_requires4(_a,_b,_c,_d,_C)                        \
      77              _GLIBCXX_CLASS_REQUIRES4(_a, _b, _c, _d, __gnu_cxx, _C);
      78  
      79  #endif // enable/disable
      80  
      81  #endif // _GLIBCXX_CONCEPT_CHECK