freebsd-dev/contrib/libstdc++/include/bits/stl_pair.h

158 lines
5.6 KiB
C++

// Pair implementation -*- C++ -*-
// Copyright (C) 2001 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file stl_pair.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
#ifndef __GLIBCPP_INTERNAL_PAIR_H
#define __GLIBCPP_INTERNAL_PAIR_H
namespace std
{
/// pair holds two objects of arbitrary type.
template <class _T1, class _T2>
struct pair {
typedef _T1 first_type; ///< @c first_type is the first bound type
typedef _T2 second_type; ///< @c second_type is the second bound type
_T1 first; ///< @c first is a copy of the first object
_T2 second; ///< @c second is a copy of the second object
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
//265. std::pair::pair() effects overly restrictive
/** The default constructor creates @c first and @c second using their
* respective default constructors. */
pair() : first(), second() {}
#else
pair() : first(_T1()), second(_T2()) {}
#endif
/** Two objects may be passed to a @c pair constructor to be copied. */
pair(const _T1& __a, const _T2& __b) : first(__a), second(__b) {}
/** There is also a templated copy ctor for the @c pair class itself. */
template <class _U1, class _U2>
pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {}
};
/// Two pairs of the same type are equal iff their members are equal.
template <class _T1, class _T2>
inline bool operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
{
return __x.first == __y.first && __x.second == __y.second;
}
/// <http://gcc.gnu.org/onlinedocs/libstdc++/20_util/howto.html#pairlt>
template <class _T1, class _T2>
inline bool operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
{
return __x.first < __y.first ||
(!(__y.first < __x.first) && __x.second < __y.second);
}
/// Uses @c operator== to find the result.
template <class _T1, class _T2>
inline bool operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) {
return !(__x == __y);
}
/// Uses @c operator< to find the result.
template <class _T1, class _T2>
inline bool operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) {
return __y < __x;
}
/// Uses @c operator< to find the result.
template <class _T1, class _T2>
inline bool operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) {
return !(__y < __x);
}
/// Uses @c operator< to find the result.
template <class _T1, class _T2>
inline bool operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) {
return !(__x < __y);
}
/**
* @brief A convenience wrapper for creating a pair from two objects.
* @param x The first object.
* @param y The second object.
* @return A newly-constructed pair<> object of the appropriate type.
*
* The standard requires that the objects be passed by reference-to-const,
* but LWG issue #181 says they should be passed by const value. We follow
* the LWG by default.
*/
template <class _T1, class _T2>
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
//181. make_pair() unintended behavior
inline pair<_T1, _T2> make_pair(_T1 __x, _T2 __y)
#else
inline pair<_T1, _T2> make_pair(const _T1& __x, const _T2& __y)
#endif
{
return pair<_T1, _T2>(__x, __y);
}
} // namespace std
#endif /* __GLIBCPP_INTERNAL_PAIR_H */
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// mode:C++
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