// Copyright 2005-2009 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 example illustrates how to use boost::hash with a custom hash function. // The implementation is contained in books.cpp #include #include namespace library { struct book { int id; std::string author; std::string title; book(int i, std::string const& a, std::string const& t) : id(i), author(a), title(t) {} }; bool operator==(book const&, book const&); std::size_t hash_value(book const&); }