forked from boostorg/unordered
96 lines
2.0 KiB
C++
96 lines
2.0 KiB
C++
// Copyright 2021 Christian Mazakas.
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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// clang-format off
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#include "../helpers/prefix.hpp"
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#include <boost/unordered_set.hpp>
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#include <boost/unordered_map.hpp>
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#include "../helpers/postfix.hpp"
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// clang-format on
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#include "../helpers/test.hpp"
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#include <boost/container_hash/hash.hpp>
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struct key
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{
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int x_;
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static int count_;
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key(int x) : x_(x) { ++count_; }
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key(key const& k) : x_(k.x_) { ++count_; }
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key& operator=(key const& k)
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{
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x_ = k.x_;
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++count_;
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return *this;
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}
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};
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int key::count_;
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struct transparent_hasher
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{
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typedef void is_transparent;
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std::size_t operator()(key const& k) const
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{
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return boost::hash<int>()(k.x_);
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}
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std::size_t operator()(int const k) const { return boost::hash<int>()(k); }
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};
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struct transparent_key_equal
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{
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typedef void is_transparent;
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static bool was_called_;
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bool operator()(key const& k1, key const& k2) const { return k1.x_ == k2.x_; }
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bool operator()(int const x, key const& k1) const
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{
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was_called_ = true;
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return k1.x_ == x;
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}
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};
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bool transparent_key_equal::was_called_;
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UNORDERED_AUTO_TEST (unordered_map_transparent_count) {
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key::count_ = 0;
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transparent_key_equal::was_called_ = false;
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boost::unordered_map<key, int, transparent_hasher, transparent_key_equal> map;
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// initial `key(0)` expression increases the count
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// then copying into the `unordered_map` increments the count again thus we
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// have 2
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//
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map[key(0)] = 1337;
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BOOST_TEST(key::count_ == 2);
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// now the number of `key` objects created should be a constant and never
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// touched again
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//
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std::size_t count = 0;
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count = map.count(0);
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BOOST_TEST(count == 1);
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BOOST_TEST(key::count_ == 2);
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BOOST_TEST(map.key_eq().was_called_);
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count = map.count(1);
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BOOST_TEST(count == 0);
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BOOST_TEST(key::count_ == 2);
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count = map.count(key(0));
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BOOST_TEST(count == 1);
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BOOST_TEST(key::count_ > 2);
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}
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RUN_TESTS()
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