Line data    Source code

       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      187510 :     const typename P::first_type& operator()(const P& y) const
      65             :     {
      66      187510 :         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        2182 :     const typename P::second_type& operator()(const P& y) const
      75             :     {
      76        2182 :         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         596 : class unary_compose : public std::unary_function<typename F2::argument_type, typename F1::result_type>
      83             : {
      84             :     public:
      85         280 :         unary_compose(const F1& fnction1, const F2& fnction2) : ftor1(fnction1), ftor2(fnction2) {}
      86             : 
      87         254 :         typename F1::result_type operator()(const typename F2::argument_type& y) const
      88             :         {
      89         254 :             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         277 : inline unary_compose<F1, F2> compose1(const F1& fnction1, const F2& fnction2)
     100             : {
     101         277 :     return unary_compose<F1, F2>(fnction1, fnction2);
     102             : }
     103             : 
     104             : }   // namespace o3tl
     105             : 
     106             : #endif
     107             : 
     108             : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */