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