# concept_check.h

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    00001 // Concept-checking control -*- C++ -*-
    00002
    00003 // Copyright (C) 2001 Free Software Foundation, Inc.
    00004 //
    00005 // This file is part of the GNU ISO C++ Library.  This library is free
    00006 // software; you can redistribute it and/or modify it under the
    00007 // terms of the GNU General Public License as published by the
    00008 // Free Software Foundation; either version 2, or (at your option)
    00009 // any later version.
    00010
    00011 // This library is distributed in the hope that it will be useful,
    00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00014 // GNU General Public License for more details.
    00015
    00016 // You should have received a copy of the GNU General Public License along
    00017 // with this library; see the file COPYING.  If not, write to the Free
    00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00019 // USA.
    00020
    00021 // As a special exception, you may use this file as part of a free software
    00022 // library without restriction.  Specifically, if other files instantiate
    00023 // templates or use macros or inline functions from this file, or you compile
    00024 // this file and link it with other files to produce an executable, this
    00025 // file does not by itself cause the resulting executable to be covered by
    00026 // the GNU General Public License.  This exception does not however
    00027 // invalidate any other reasons why the executable file might be covered by
    00028 // the GNU General Public License.
    00029
    00030 /** @file concept_check.h
    00031  *  This is an internal header file, included by other library headers.
    00032  *  You should not attempt to use it directly.
    00033  */
    00034
    00035 #ifndef _CONCEPT_CHECK_H
    00036 #define _CONCEPT_CHECK_H 1
    00037
    00038 #pragma GCC system_header
    00039
    00040 #include <bits/c++config.h>
    00041
    00042 // All places in libstdc++-v3 where these are used, or /might/ be used, or
    00043 // don't need to be used, or perhaps /should/ be used, are commented with
    00044 // "concept requirements" (and maybe some more text).  So grep like crazy
    00045 // if you're looking for additional places to use these.
    00046
    00047 // Concept-checking code is off by default unless users turn it on via
    00048 // configure options or editing c++config.h.
    00049
    00050 #ifndef _GLIBCXX_CONCEPT_CHECKS
    00051
    00052 #define __glibcxx_function_requires(...)
    00053 #define __glibcxx_class_requires(_a,_b)
    00054 #define __glibcxx_class_requires2(_a,_b,_c)
    00055 #define __glibcxx_class_requires3(_a,_b,_c,_d)
    00056 #define __glibcxx_class_requires4(_a,_b,_c,_d,_e)
    00057
    00058 #else // the checks are on
    00059
    00060 #include <bits/boost_concept_check.h>
    00061
    00062 // Note that the obvious and elegant approach of
    00063 //
    00064 //#define glibcxx_function_requires(C) boost::function_requires< boost::C >()
    00065 //
    00066 // won't work due to concept templates with more than one parameter, e.g.,
    00067 // BinaryPredicateConcept.  The preprocessor tries to split things up on
    00068 // the commas in the template argument list.  We can't use an inner pair of
    00069 // parenthesis to hide the commas, because "boost::(Temp<Foo,Bar>)" isn't
    00070 // a valid instantiation pattern.  Thus, we steal a feature from C99.
    00071
    00072 #define __glibcxx_function_requires(...)                                 \
    00073             __gnu_cxx::__function_requires< __gnu_cxx::__VA_ARGS__ >();
    00074 #define __glibcxx_class_requires(_a,_C)                                  \
    00075             _GLIBCXX_CLASS_REQUIRES(_a, __gnu_cxx, _C);
    00076 #define __glibcxx_class_requires2(_a,_b,_C)                              \
    00077             _GLIBCXX_CLASS_REQUIRES2(_a, _b, __gnu_cxx, _C);
    00078 #define __glibcxx_class_requires3(_a,_b,_c,_C)                           \
    00079             _GLIBCXX_CLASS_REQUIRES3(_a, _b, _c, __gnu_cxx, _C);
    00080 #define __glibcxx_class_requires4(_a,_b,_c,_d,_C)                        \
    00081             _GLIBCXX_CLASS_REQUIRES4(_a, _b, _c, _d, __gnu_cxx, _C);
    00082
    00083 #endif // enable/disable
    00084
    00085 #endif // _GLIBCXX_CONCEPT_CHECK