Added thirdparty: boost library

thirdparty/include/boost/unordered/hash_traits.hpp

@@ -0,0 +1,44 @@
+/* Hash function characterization.
+ *
+ * Copyright 2022 Joaquin M Lopez Munoz.
+ * 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)
+ *
+ * See https://www.boost.org/libs/unordered for library home page.
+ */
+
+#ifndef BOOST_UNORDERED_HASH_TRAITS_HPP
+#define BOOST_UNORDERED_HASH_TRAITS_HPP
+
+#include <boost/unordered/detail/type_traits.hpp>
+
+namespace boost{
+namespace unordered{
+
+namespace detail{
+
+template<typename Hash,typename=void>
+struct hash_is_avalanching_impl: std::false_type{};
+
+template<typename Hash>
+struct hash_is_avalanching_impl<Hash,
+  boost::unordered::detail::void_t<typename Hash::is_avalanching> >:
+    std::true_type{};
+
+} /* namespace detail */
+
+/* Each trait can be partially specialized by users for concrete hash functions
+ * when actual characterization differs from default.
+ */
+
+/* hash_is_avalanching<Hash>::value is true when the type Hash::is_avalanching
+ * is present, false otherwise.
+ */
+template<typename Hash>
+struct hash_is_avalanching: detail::hash_is_avalanching_impl<Hash>::type{};
+
+} /* namespace unordered */
+} /* namespace boost */
+
+#endif