Merge branch 'vendor/GCC44'
[dragonfly.git] / contrib / gcc-4.4 / libstdc++-v3 / include / backward / binders.h
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1// Functor implementations -*- C++ -*-
2
3// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library. This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 3, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15// GNU General Public License for more details.
16
17// Under Section 7 of GPL version 3, you are granted additional
18// permissions described in the GCC Runtime Library Exception, version
19// 3.1, as published by the Free Software Foundation.
20
21// You should have received a copy of the GNU General Public License and
22// a copy of the GCC Runtime Library Exception along with this program;
23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24// <http://www.gnu.org/licenses/>.
25
26/*
27 *
28 * Copyright (c) 1994
29 * Hewlett-Packard Company
30 *
31 * Permission to use, copy, modify, distribute and sell this software
32 * and its documentation for any purpose is hereby granted without fee,
33 * provided that the above copyright notice appear in all copies and
34 * that both that copyright notice and this permission notice appear
35 * in supporting documentation. Hewlett-Packard Company makes no
36 * representations about the suitability of this software for any
37 * purpose. It is provided "as is" without express or implied warranty.
38 *
39 *
40 * Copyright (c) 1996-1998
41 * Silicon Graphics Computer Systems, Inc.
42 *
43 * Permission to use, copy, modify, distribute and sell this software
44 * and its documentation for any purpose is hereby granted without fee,
45 * provided that the above copyright notice appear in all copies and
46 * that both that copyright notice and this permission notice appear
47 * in supporting documentation. Silicon Graphics makes no
48 * representations about the suitability of this software for any
49 * purpose. It is provided "as is" without express or implied warranty.
50 */
51
52/** @file backward/binders.h
53 * This is an internal header file, included by other library headers.
54 * You should not attempt to use it directly.
55 */
56
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57#ifndef _BACKWARD_BINDERS_H
58#define _BACKWARD_BINDERS_H 1
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59
60_GLIBCXX_BEGIN_NAMESPACE(std)
61
62 // 20.3.6 binders
63 /** @defgroup binders Binder Classes
64 * @ingroup functors
65 *
66 * Binders turn functions/functors with two arguments into functors with
67 * a single argument, storing an argument to be applied later. For
68 * example, a variable @c B of type @c binder1st is constructed from a
69 * functor @c f and an argument @c x. Later, B's @c operator() is called
70 * with a single argument @c y. The return value is the value of @c f(x,y).
71 * @c B can be "called" with various arguments (y1, y2, ...) and will in
72 * turn call @c f(x,y1), @c f(x,y2), ...
73 *
74 * The function @c bind1st is provided to save some typing. It takes the
75 * function and an argument as parameters, and returns an instance of
76 * @c binder1st.
77 *
78 * The type @c binder2nd and its creator function @c bind2nd do the same
79 * thing, but the stored argument is passed as the second parameter instead
80 * of the first, e.g., @c bind2nd(std::minus<float>,1.3) will create a
81 * functor whose @c operator() accepts a floating-point number, subtracts
82 * 1.3 from it, and returns the result. (If @c bind1st had been used,
83 * the functor would perform "1.3 - x" instead.
84 *
85 * Creator-wrapper functions like @c bind1st are intended to be used in
86 * calling algorithms. Their return values will be temporary objects.
87 * (The goal is to not require you to type names like
88 * @c std::binder1st<std::plus<int>> for declaring a variable to hold the
89 * return value from @c bind1st(std::plus<int>,5).
90 *
91 * These become more useful when combined with the composition functions.
92 *
93 * @{
94 */
95 /// One of the @link binders binder functors@endlink.
96 template<typename _Operation>
97 class binder1st
98 : public unary_function<typename _Operation::second_argument_type,
99 typename _Operation::result_type>
100 {
101 protected:
102 _Operation op;
103 typename _Operation::first_argument_type value;
104
105 public:
106 binder1st(const _Operation& __x,
107 const typename _Operation::first_argument_type& __y)
108 : op(__x), value(__y) { }
109
110 typename _Operation::result_type
111 operator()(const typename _Operation::second_argument_type& __x) const
112 { return op(value, __x); }
113
114 // _GLIBCXX_RESOLVE_LIB_DEFECTS
115 // 109. Missing binders for non-const sequence elements
116 typename _Operation::result_type
117 operator()(typename _Operation::second_argument_type& __x) const
118 { return op(value, __x); }
119 } _GLIBCXX_DEPRECATED_ATTR;
120
121 /// One of the @link binders binder functors@endlink.
122 template<typename _Operation, typename _Tp>
123 inline binder1st<_Operation>
124 bind1st(const _Operation& __fn, const _Tp& __x)
125 {
126 typedef typename _Operation::first_argument_type _Arg1_type;
127 return binder1st<_Operation>(__fn, _Arg1_type(__x));
128 }
129
130 /// One of the @link binders binder functors@endlink.
131 template<typename _Operation>
132 class binder2nd
133 : public unary_function<typename _Operation::first_argument_type,
134 typename _Operation::result_type>
135 {
136 protected:
137 _Operation op;
138 typename _Operation::second_argument_type value;
139
140 public:
141 binder2nd(const _Operation& __x,
142 const typename _Operation::second_argument_type& __y)
143 : op(__x), value(__y) { }
144
145 typename _Operation::result_type
146 operator()(const typename _Operation::first_argument_type& __x) const
147 { return op(__x, value); }
148
149 // _GLIBCXX_RESOLVE_LIB_DEFECTS
150 // 109. Missing binders for non-const sequence elements
151 typename _Operation::result_type
152 operator()(typename _Operation::first_argument_type& __x) const
153 { return op(__x, value); }
154 } _GLIBCXX_DEPRECATED_ATTR;
155
156 /// One of the @link binders binder functors@endlink.
157 template<typename _Operation, typename _Tp>
158 inline binder2nd<_Operation>
159 bind2nd(const _Operation& __fn, const _Tp& __x)
160 {
161 typedef typename _Operation::second_argument_type _Arg2_type;
162 return binder2nd<_Operation>(__fn, _Arg2_type(__x));
163 }
164 /** @} */
165
166_GLIBCXX_END_NAMESPACE
167
4b1e227d 168#endif /* _BACKWARD_BINDERS_H */