1// Concept-checking control -*- C++ -*- 
2 
3// Copyright (C) 2001-2019 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) || !_GLIBCXX_HOSTED 
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 
82