upair.h

   1 // This file is part of the ustl library, an STL implementation.
   2 //
   3 // Copyright (C) 2005 by Mike Sharov <msharov@users.sourceforge.net>
   4 // This file is free software, distributed under the MIT License.
   5 //
   6 /// \file upair.h
   7 /// \brief Pair-related functionality.
   8
   9 #ifndef UPAIR_H_7DC08F1B7FECF8AE6856D84C3B617A75
  10 #define UPAIR_H_7DC08F1B7FECF8AE6856D84C3B617A75
  11
  12 #include "utypes.h"
  13
  14 namespace ustl {
  15
  16 /// \class pair upair.h ustl.h
  17 /// \ingroup AssociativeContainers
  18 ///
  19 /// \brief Container for two values.
  20 ///
  21 template <typename T1, typename T2>
  22 class pair {
  23 public:
  24     typedef T1          first_type;
  25     typedef T2          second_type;
  26 public:
  27     /// Default constructor.
  28     inline pair (void)                          : first (T1()), second (T2()) {}
  29     /// Initializes members with \p a, and \p b.
  30     inline pair (const T1& a, const T2& b)      : first (a), second (b) {}
  31     inline pair&        operator= (const pair<T1, T2>& p2) { first = p2.first; second = p2.second; return (*this); }
  32     template <typename T3, typename T4>
  33     inline pair&        operator= (const pair<T3, T4>& p2) { first = p2.first; second = p2.second; return (*this); }
  34 public:
  35     first_type          first;
  36     second_type         second;
  37 };
  38
  39 /// Compares both values of \p p1 to those of \p p2.
  40 template <typename T1, typename T2>
  41 inline bool operator== (const pair<T1,T2>& p1, const pair<T1,T2>& p2)
  42 {
  43     return (p1.first == p2.first && p1.second == p2.second);
  44 }
  45
  46 /// Compares both values of \p p1 to those of \p p2.
  47 template <typename T1, typename T2>
  48 bool operator< (const pair<T1,T2>& p1, const pair<T1,T2>& p2)
  49 {
  50     return (p1.first < p2.first || (p1.first == p2.first && p1.second < p2.second));
  51 }
  52
  53 /// Returns a pair object with (a,b)
  54 template <typename T1, typename T2>
  55 inline pair<T1,T2> make_pair (const T1& a, const T2& b)
  56 {
  57     return (pair<T1,T2> (a, b));
  58 }
  59
  60 } // namespace ustl
  61
  62 #endif
  63