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[SVN r12390]
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249
binary_search_test.cpp
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249
binary_search_test.cpp
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// (C) Copyright David Abrahams 2000. Permission to copy, use, modify,
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// sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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#include <vector>
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#include <string>
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#include <memory>
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#include <climits>
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#include <iostream>
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#include <cassert>
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#include <stdlib.h> // for rand(). Would use cstdlib but VC6.4 doesn't put it in std::
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#include <list>
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#include <algorithm>
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#include <boost/detail/binary_search.hpp>
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#if defined(__SGI_STL_PORT) ? defined(__SGI_STL_OWN_IOSTREAMS) : (!defined(__GNUC__) || __GNUC__ > 2)
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# define USE_SSTREAM
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#endif
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#ifdef USE_SSTREAM
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# include <sstream>
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#else
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# include <strstream>
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#endif
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namespace {
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typedef std::vector<std::string> string_vector;
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const std::size_t sequence_length = 1000;
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unsigned random_number()
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{
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return static_cast<unsigned>(::rand()) % sequence_length;
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}
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# ifndef USE_SSTREAM
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class unfreezer {
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public:
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unfreezer(std::ostrstream& s) : m_stream(s) {}
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~unfreezer() { m_stream.freeze(false); }
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private:
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std::ostrstream& m_stream;
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};
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# endif
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template <class T>
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void push_back_random_number_string(T& seq)
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{
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unsigned value = random_number();
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# if defined(__SGI_STL_PORT) ? defined(__SGI_STL_OWN_IOSTREAMS) : (!defined(__GNUC__) || __GNUC__ > 2)
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std::ostringstream s;
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s << value;
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seq.push_back(s.str());
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# else
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std::ostrstream s;
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auto unfreezer unfreeze(s);
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s << value << char(0);
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seq.push_back(std::string(s.str()));
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# endif
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}
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inline unsigned to_int(unsigned x) { return x; }
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inline unsigned to_int(const std::string& x) { return atoi(x.c_str()); }
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struct cmp
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{
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template <class A1, class A2>
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inline bool operator()(const A1& a1, const A2& a2) const
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{
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return to_int(a1) < to_int(a2);
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}
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};
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inline bool operator<(const std::string& x, const unsigned y)
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{
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return to_int(x) < y;
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}
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inline bool operator<(const unsigned y, const std::string& x)
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{
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return y < to_int(x);
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}
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template <class T> void sort_by_value(T&);
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template <>
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void sort_by_value(std::vector<std::string>& v)
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{
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std::sort(v.begin(), v.end(), cmp());
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}
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template <class T>
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void random_sorted_sequence(T& seq)
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{
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seq.clear();
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for (std::size_t i = 0; i < sequence_length; ++i)
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{
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push_back_random_number_string(seq);
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}
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sort_by_value(seq);
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}
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# if defined(BOOST_MSVC) && !defined(__SGI_STL_PORT)
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// VC6's standard lib doesn't have a template member function for list::sort()
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template <>
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void random_sorted_sequence(std::list<std::string>& result)
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{
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std::vector<std::string> seq;
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seq.reserve(sequence_length);
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for (std::size_t i = 0; i < sequence_length; ++i)
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{
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push_back_random_number_string(seq);
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}
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sort_by_value(seq);
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result.resize(seq.size());
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std::copy(seq.begin(), seq.end(), result.begin());
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}
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#else
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template <>
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inline void sort_by_value(std::list<std::string>& l)
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{
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l.sort(cmp());
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}
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# endif
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// A way to select the comparisons with/without a Compare parameter for testing.
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template <class Compare> struct searches
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{
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template <class Iterator, class Key>
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static Iterator lower_bound(Iterator start, Iterator finish, Key key, Compare cmp)
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{ return boost::detail::lower_bound(start, finish, key, cmp); }
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template <class Iterator, class Key>
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static Iterator upper_bound(Iterator start, Iterator finish, Key key, Compare cmp)
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{ return boost::detail::upper_bound(start, finish, key, cmp); }
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template <class Iterator, class Key>
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static std::pair<Iterator, Iterator> equal_range(Iterator start, Iterator finish, Key key, Compare cmp)
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{ return boost::detail::equal_range(start, finish, key, cmp); }
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template <class Iterator, class Key>
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static bool binary_search(Iterator start, Iterator finish, Key key, Compare cmp)
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{ return boost::detail::binary_search(start, finish, key, cmp); }
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};
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struct no_compare {};
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template <> struct searches<no_compare>
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{
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template <class Iterator, class Key>
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static Iterator lower_bound(Iterator start, Iterator finish, Key key, no_compare)
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{ return boost::detail::lower_bound(start, finish, key); }
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template <class Iterator, class Key>
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static Iterator upper_bound(Iterator start, Iterator finish, Key key, no_compare)
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{ return boost::detail::upper_bound(start, finish, key); }
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template <class Iterator, class Key>
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static std::pair<Iterator, Iterator> equal_range(Iterator start, Iterator finish, Key key, no_compare)
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{ return boost::detail::equal_range(start, finish, key); }
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template <class Iterator, class Key>
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static bool binary_search(Iterator start, Iterator finish, Key key, no_compare)
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{ return boost::detail::binary_search(start, finish, key); }
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};
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template <class Sequence, class Compare>
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void test_loop(Sequence& x, Compare cmp, unsigned long test_count)
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{
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typedef typename Sequence::const_iterator const_iterator;
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for (unsigned long i = 0; i < test_count; ++i)
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{
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random_sorted_sequence(x);
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const const_iterator start = x.begin();
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const const_iterator finish = x.end();
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unsigned key = random_number();
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const const_iterator l = searches<Compare>::lower_bound(start, finish, key, cmp);
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const const_iterator u = searches<Compare>::upper_bound(start, finish, key, cmp);
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bool found_l = false;
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bool found_u = false;
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std::size_t index = 0;
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std::size_t count = 0;
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unsigned last_value = 0;
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for (const_iterator p = start; p != finish; ++p)
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{
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if (p == l)
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found_l = true;
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if (p == u)
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{
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assert(found_l);
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found_u = true;
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}
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unsigned value = to_int(*p);
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assert(value >= last_value);
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last_value = value;
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if (!found_l)
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{
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++index;
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assert(to_int(*p) < key);
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}
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else if (!found_u)
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{
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++count;
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assert(to_int(*p) == key);
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}
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else
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assert(to_int(*p) > key);
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}
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assert(found_l || l == finish);
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assert(found_u || u == finish);
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std::pair<const_iterator, const_iterator>
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range = searches<Compare>::equal_range(start, finish, key, cmp);
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assert(range.first == l);
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assert(range.second == u);
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bool found = searches<Compare>::binary_search(start, finish, key, cmp);
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assert(found == (u != l));
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std::cout << "found " << count << " copies of " << key << " at index " << index << "\n";
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}
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}
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}
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int main()
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{
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std::vector<std::string> x;
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std::cout << "=== testing random-access iterators with <: ===\n";
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test_loop(x, no_compare(), 25);
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std::cout << "=== testing random-access iterators with compare: ===\n";
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test_loop(x, cmp(), 25);
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std::list<std::string> y;
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std::cout << "=== testing bidirectional iterators with <: ===\n";
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test_loop(y, no_compare(), 25);
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std::cout << "=== testing bidirectional iterators with compare: ===\n";
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test_loop(y, cmp(), 25);
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std::cerr << "******TEST PASSED******\n";
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return 0;
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}
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