container_hash/examples/template.hpp
2017-12-29 13:58:48 +00:00

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C++

// Copyright 2012 Daniel James.
// 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)
// This is an example of how to write a hash function for a template
// class.
#include <boost/container_hash/hash_fwd.hpp>
template <typename A, typename B>
class my_pair
{
A value1;
B value2;
public:
my_pair(A const& v1, B const& v2)
: value1(v1), value2(v2)
{}
bool operator==(my_pair const& other) const
{
return value1 == other.value1 &&
value2 == other.value2;
}
friend std::size_t hash_value(my_pair const& p)
{
std::size_t seed = 0;
boost::hash_combine(seed, p.value1);
boost::hash_combine(seed, p.value2);
return seed;
}
};