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// boost variant/detail/hash_variant.hpp header file
// See for updates, documentation, and revision history.
// Copyright (c) 2011
// Antony Polukhin
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at


#if defined(_MSC_VER)
# pragma once

#include <boost/variant/variant_fwd.hpp>
#include <boost/variant/static_visitor.hpp>
#include <boost/variant/apply_visitor.hpp>
#include <boost/functional/hash_fwd.hpp>

namespace boost {

    namespace detail { namespace variant {
        struct variant_hasher: public boost::static_visitor<std::size_t> {
            template <class T>
            std::size_t operator()(T const& val) const {
                boost::hash<T> hasher;
                return hasher(val);

    template < BOOST_VARIANT_ENUM_PARAMS(typename T) >
    std::size_t hash_value(variant< BOOST_VARIANT_ENUM_PARAMS(T) > const& val) {
        std::size_t seed = boost::apply_visitor(detail::variant::variant_hasher(), val);
        hash_combine(seed, val.which());
        return seed;