1 files changed, 48 insertions, 0 deletions
diff --git a/boost/variant/detail/hash_variant.hpp b/boost/variant/detail/hash_variant.hpp
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+++ b/boost/variant/detail/hash_variant.hpp
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+//-----------------------------------------------------------------------------
+// boost variant/detail/hash_variant.hpp header file
+// See http://www.boost.org 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
+// http://www.boost.org/LICENSE_1_0.txt)
+
+
+#ifndef BOOST_HASH_VARIANT_FUNCTION_HPP
+#define BOOST_HASH_VARIANT_FUNCTION_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#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 {
+                using namespace 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;
+    }
+}
+
+#endif
+