algorithm/test/partition_point_test1.cpp

/* 
   Copyright (c) Marshall Clow 2011-2012.

   Distributed under the Boost Software License, Version 1.0. (See accompanying
   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

    For more information, see http://www.boost.org
*/

#include <iostream>

#include <boost/config.hpp>
#include <boost/algorithm/cxx11/partition_point.hpp>

#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>

#include <string>
#include <vector>
#include <list>

namespace ba = boost::algorithm;
// namespace ba = boost;

template <typename Container>
typename Container::iterator offset_to_iter ( Container &v, int offset ) {
    typename Container::iterator retval;
    
    if ( offset >= 0 ) {
        retval = v.begin ();
        std::advance ( retval, offset );
        }
    else {
        retval = v.end ();
        std::advance ( retval, offset + 1 );
        }
    return retval;
    }

template <typename Container, typename Predicate>
void test_sequence ( Container &v, Predicate comp, int expected ) {
    typename Container::iterator res, exp;
    
    res = ba::partition_point ( v.begin (), v.end (), comp );
    exp = offset_to_iter ( v, expected );
    BOOST_CHECK ( exp == res );

//  Duplicate the last element; this checks for any even/odd problems
    v.push_back ( * v.rbegin ());
    res = ba::partition_point ( v.begin (), v.end (), comp );
    exp = offset_to_iter ( v, expected );
    BOOST_CHECK ( exp == res );

//  Range based test
    res = ba::partition_point ( v, comp );
    exp = offset_to_iter ( v, expected );
    BOOST_CHECK ( exp == res );
    }

template <typename T>
struct less_than {
public:
    less_than ( T foo ) : val ( foo ) {}
    less_than ( const less_than &rhs ) : val ( rhs.val ) {}

    bool operator () ( const T &v ) const { return v < val; }
private:
    less_than ();
    less_than operator = ( const less_than &rhs );
    T val;
    };


void test_sequence1 () {
    std::vector<int> v;
    
    v.clear ();
    for ( int i = 5; i < 15; ++i )
        v.push_back ( i );
    test_sequence ( v, less_than<int>(3),  0 ); // no elements
    test_sequence ( v, less_than<int>(6),  1 );    // only the first element
    test_sequence ( v, less_than<int>(10), 5 );
    test_sequence ( v, less_than<int>(99), -1 );   // all elements satisfy 

//  With bidirectional iterators.
    std::list<int> l;
    for ( int i = 5; i < 15; ++i )
        l.push_back ( i );
    test_sequence ( l, less_than<int>(3),  0 ); // no elements
    test_sequence ( l, less_than<int>(6),  1 );    // only the first element
    test_sequence ( l, less_than<int>(10), 5 );
    test_sequence ( l, less_than<int>(99), -1 );   // all elements satisfy 

    }


BOOST_AUTO_TEST_CASE( test_main )
{
  test_sequence1 ();
}