1/*
2 Copyright (c) Marshall Clow 2008-2012.
3
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6*/
7
8/// \file equal.hpp
9/// \brief Test ranges to if they are equal
10/// \author Marshall Clow
11
12#ifndef BOOST_ALGORITHM_EQUAL_HPP
13#define BOOST_ALGORITHM_EQUAL_HPP
14
15#include <iterator>
16
17#include <boost/config.hpp>
18
19namespace boost { namespace algorithm {
20
21namespace detail {
22
23 template <class T1, class T2>
24 struct eq {
25 BOOST_CONSTEXPR bool operator () ( const T1& v1, const T2& v2 ) const { return v1 == v2 ;}
26 };
27
28 template <class RandomAccessIterator1, class RandomAccessIterator2, class BinaryPredicate>
29 BOOST_CXX14_CONSTEXPR
30 bool equal ( RandomAccessIterator1 first1, RandomAccessIterator1 last1,
31 RandomAccessIterator2 first2, RandomAccessIterator2 last2, BinaryPredicate pred,
32 std::random_access_iterator_tag, std::random_access_iterator_tag )
33 {
34 // Random-access iterators let is check the sizes in constant time
35 if ( std::distance ( first1, last1 ) != std::distance ( first2, last2 ))
36 return false;
37
38 // std::equal
39 for (; first1 != last1; ++first1, ++first2)
40 if (!pred(*first1, *first2))
41 return false;
42 return true;
43 }
44
45 template <class InputIterator1, class InputIterator2, class BinaryPredicate>
46 BOOST_CXX14_CONSTEXPR
47 bool equal ( InputIterator1 first1, InputIterator1 last1,
48 InputIterator2 first2, InputIterator2 last2, BinaryPredicate pred,
49 std::input_iterator_tag, std::input_iterator_tag )
50 {
51 for (; first1 != last1 && first2 != last2; ++first1, ++first2 )
52 if ( !pred(*first1, *first2 ))
53 return false;
54
55 return first1 == last1 && first2 == last2;
56 }
57}
58
59/// \fn equal ( InputIterator1 first1, InputIterator1 last1,
60/// InputIterator2 first2, InputIterator2 last2,
61/// BinaryPredicate pred )
62/// \return true if all elements in the two ranges are equal
63///
64/// \param first1 The start of the first range.
65/// \param last1 One past the end of the first range.
66/// \param first2 The start of the second range.
67/// \param last2 One past the end of the second range.
68/// \param pred A predicate for comparing the elements of the ranges
69template <class InputIterator1, class InputIterator2, class BinaryPredicate>
70BOOST_CXX14_CONSTEXPR
71bool equal ( InputIterator1 first1, InputIterator1 last1,
72 InputIterator2 first2, InputIterator2 last2, BinaryPredicate pred )
73{
74 return boost::algorithm::detail::equal (
75 first1, last1, first2, last2, pred,
76 typename std::iterator_traits<InputIterator1>::iterator_category (),
77 typename std::iterator_traits<InputIterator2>::iterator_category ());
78}
79
80/// \fn equal ( InputIterator1 first1, InputIterator1 last1,
81/// InputIterator2 first2, InputIterator2 last2 )
82/// \return true if all elements in the two ranges are equal
83///
84/// \param first1 The start of the first range.
85/// \param last1 One past the end of the first range.
86/// \param first2 The start of the second range.
87/// \param last2 One past the end of the second range.
88template <class InputIterator1, class InputIterator2>
89BOOST_CXX14_CONSTEXPR
90bool equal ( InputIterator1 first1, InputIterator1 last1,
91 InputIterator2 first2, InputIterator2 last2 )
92{
93 return boost::algorithm::detail::equal (
94 first1, last1, first2, last2,
95 boost::algorithm::detail::eq<
96 typename std::iterator_traits<InputIterator1>::value_type,
97 typename std::iterator_traits<InputIterator2>::value_type> (),
98 typename std::iterator_traits<InputIterator1>::iterator_category (),
99 typename std::iterator_traits<InputIterator2>::iterator_category ());
100}
101
102// There are already range-based versions of these.
103
104}} // namespace boost and algorithm
105
106#endif // BOOST_ALGORITHM_EQUAL_HPP
107

source code of boost/libs/algorithm/include/boost/algorithm/cxx14/equal.hpp