src/util/utility.h

   1 /*********************                                                        */
   2 /*! \file utility.h
   3  ** \verbatim
   4  ** Original author: Morgan Deters
   5  ** Major contributors: none
   6  ** Minor contributors (to current version): none
   7  ** This file is part of the CVC4 project.
   8  ** Copyright (c) 2009-2014  New York University and The University of Iowa
   9  ** See the file COPYING in the top-level source directory for licensing
  10  ** information.\endverbatim
  11  **
  12  ** \brief Some standard STL-related utility functions for CVC4
  13  **
  14  ** Some standard STL-related utility functions for CVC4.
  15  **/
  16
  17 #include "cvc4_private.h"
  18
  19 #ifndef __CVC4__UTILITY_H
  20 #define __CVC4__UTILITY_H
  21
  22 #include <utility>
  23 #include <functional>
  24
  25 namespace CVC4 {
  26
  27
  28 /**
  29  * Like std::equal_to<>, but tests equality between the first element
  30  * of a pair and an element.
  31  */
  32 template <class T, class U>
  33 struct first_equal_to : std::binary_function<std::pair<T, U>, T, bool> {
  34   bool operator()(const std::pair<T, U>& pr, const T& x) const {
  35     return pr.first == x;
  36   }
  37 };/* struct first_equal_to<T> */
  38
  39
  40 /**
  41  * Like std::equal_to<>, but tests equality between the second element
  42  * of a pair and an element.
  43  */
  44 template <class T, class U>
  45 struct second_equal_to : std::binary_function<std::pair<T, U>, U, bool> {
  46   bool operator()(const std::pair<T, U>& pr, const U& x) const {
  47     return pr.second == x;
  48   }
  49 };/* struct first_equal_to<T> */
  50
  51
  52 /**
  53  * Using std::find_if(), finds the first iterator in [first,last)
  54  * range that satisfies predicate.  If none, return last; otherwise,
  55  * search for a second one.  If there IS a second one, return last,
  56  * otherwise return the first (and unique) iterator satisfying pred().
  57  */
  58 template <class InputIterator, class Predicate>
  59 inline InputIterator find_if_unique(InputIterator first, InputIterator last, Predicate pred) {
  60   InputIterator match = std::find_if(first, last, pred);
  61   if(match == last) {
  62     return last;
  63   }
  64
  65   InputIterator match2 = match;
  66   match2 = std::find_if(++match2, last, pred);
  67   return (match2 == last) ? match : last;
  68 }
  69
  70 }/* CVC4 namespace */
  71
  72 #endif /* __CVC4__UTILITY_H */