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1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : /*
3 : *
4 : * Copyright (c) 1994
5 : * Hewlett-Packard Company
6 : *
7 : * Copyright (c) 1996-1998
8 : * Silicon Graphics Computer Systems, Inc.
9 : *
10 : * Copyright (c) 1997
11 : * Moscow Center for SPARC Technology
12 : *
13 : * Copyright (c) 1999
14 : * Boris Fomitchev
15 : *
16 : * This material is provided "as is", with absolutely no warranty expressed
17 : * or implied. Any use is at your own risk.
18 : *
19 : * Permission to use or copy this software for any purpose is hereby granted
20 : * without fee, provided the above notices are retained on all copies.
21 : * Permission to modify the code and to distribute modified code is granted,
22 : * provided the above notices are retained, and a notice that the code was
23 : * modified is included with the above copyright notice.
24 : *
25 : */
26 :
27 : /*
28 : * Lifted and paraphrased from STLport - with additions from Fridrich
29 : * Strba and Thorsten Behrens
30 : */
31 :
32 : #ifndef INCLUDED_O3TL_COMPAT_FUNCTIONAL_HXX
33 : #define INCLUDED_O3TL_COMPAT_FUNCTIONAL_HXX
34 :
35 : #include <functional>
36 :
37 : namespace o3tl
38 : {
39 :
40 : /// Functor, given two parameters, return the first
41 : template<class T1,class T2>
42 : struct project1st : public std::binary_function<T1, T2, T1>
43 : {
44 : T1 operator()(const T1& y, const T2&) const
45 : {
46 : return (y);
47 : }
48 : };
49 :
50 : /// Functor, given two parameters, return the second
51 : template<class T1,class T2>
52 : struct project2nd : public std::binary_function<T1, T2, T2>
53 : {
54 : T2 operator()(const T1&, const T2& x) const
55 : {
56 : return (x);
57 : }
58 : };
59 :
60 : /// Select first value of a pair
61 : template<class P>
62 : struct select1st : public std::unary_function<P, typename P::first_type>
63 : {
64 384954 : const typename P::first_type& operator()(const P& y) const
65 : {
66 384954 : return (y.first);
67 : }
68 : };
69 :
70 : /// Select second value of a pair
71 : template<class P>
72 : struct select2nd : public std::unary_function<P, typename P::second_type>
73 : {
74 1570 : const typename P::second_type& operator()(const P& y) const
75 : {
76 1570 : return (y.second);
77 : }
78 : };
79 :
80 : /// Call F1 with the result of F2 applied to the one input parameter
81 : template<class F1, class F2>
82 1570 : class unary_compose : public std::unary_function<typename F2::argument_type, typename F1::result_type>
83 : {
84 : public:
85 194 : unary_compose(const F1& fnction1, const F2& fnction2) : ftor1(fnction1), ftor2(fnction2) {}
86 :
87 44 : typename F1::result_type operator()(const typename F2::argument_type& y) const
88 : {
89 44 : return (ftor1(ftor2(y)));
90 : }
91 :
92 : protected:
93 : F1 ftor1;
94 : F2 ftor2;
95 : };
96 :
97 : /// Create functor that calls F1 with the result of F2 applied to the one input parameter
98 : template<class F1, class F2>
99 188 : inline unary_compose<F1, F2> compose1(const F1& fnction1, const F2& fnction2)
100 : {
101 188 : return (unary_compose<F1, F2>(fnction1, fnction2));
102 : }
103 :
104 : } // namespace o3tl
105 :
106 : #endif
107 :
108 : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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