1// (C) Copyright Herve Bronnimann 2004.
2// Use, modification and distribution are subject to the
3// Boost Software License, Version 1.0. (See accompanying file
4// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6#include <utility>
7#include <functional>
8
9#include <boost/config.hpp>
10#include <boost/algorithm/minmax.hpp>
11
12#define BOOST_TEST_MAIN
13#include <boost/test/unit_test.hpp>
14
15class custom {
16 int m_x;
17 friend std::ostream& operator<<(std::ostream& str, custom const& x);
18public:
19 explicit custom(int x = 0) : m_x(x) {}
20 custom(custom const& y) : m_x(y.m_x) {}
21 bool operator==(custom const& y) const { return m_x == y.m_x; }
22 bool operator<(custom const& y) const { return m_x < y.m_x; }
23 custom operator+(custom const& y) const { return custom(m_x+y.m_x); }
24 custom& operator+=(custom const& y) { m_x += y.m_x; return *this; }
25};
26
27std::ostream&
28operator<<(std::ostream& str, custom const& x)
29{
30 return str << x.m_x;
31}
32
33template <class Value>
34struct less_count : std::less<Value> {
35 typedef std::less<Value> Base;
36 less_count(less_count<Value> const& lc) : m_counter(lc.m_counter) {}
37 less_count(int& counter) : m_counter(counter) {}
38 bool operator()(Value const& a, Value const& b) const {
39 ++m_counter;
40 return Base::operator()(a,b);
41 }
42 void reset() {
43 m_counter = 0;
44 }
45private:
46 int& m_counter;
47};
48
49using namespace boost;
50
51template <class Value>
52void test(BOOST_EXPLICIT_TEMPLATE_TYPE(Value))
53{
54 Value zero(0), one(1);
55 int counter = 0;
56 less_count<Value> lc(counter);
57
58 // Test functionality
59 tuple<Value const&, Value const&> result1 = boost::minmax(zero, one);
60 BOOST_CHECK_EQUAL( get<0>(result1), zero );
61 BOOST_CHECK_EQUAL( get<1>(result1), one );
62
63 tuple<Value const&, Value const&> result2 = boost::minmax(one, zero);
64 BOOST_CHECK_EQUAL( get<0>(result2), zero );
65 BOOST_CHECK_EQUAL( get<1>(result2), one );
66
67 // Test functionality and number of comparisons
68 lc.reset();
69 tuple<Value const&, Value const&> result3 = boost::minmax(zero, one, lc );
70 BOOST_CHECK_EQUAL( get<0>(result3), zero );
71 BOOST_CHECK_EQUAL( get<1>(result3), one );
72 BOOST_CHECK_EQUAL( counter, 1 );
73
74 lc.reset();
75 tuple<Value const&, Value const&> result4 = boost::minmax(one, zero, lc );
76 BOOST_CHECK_EQUAL( get<0>(result4), zero );
77 BOOST_CHECK_EQUAL( get<1>(result4), one );
78 BOOST_CHECK_EQUAL( counter, 1);
79}
80
81BOOST_AUTO_TEST_CASE( test_main )
82{
83 test<int>(); // ("builtin");
84 test<custom>(); // ("custom ");
85}
86

source code of boost/libs/algorithm/minmax/test/minmax_test.cpp