// last_value function object (documented as part of Boost.Signals) // Copyright Douglas Gregor 2001-2003. Use, modification and // distribution is subject to 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) // For more information, see http://www.boost.org/libs/signals #ifndef BOOST_LAST_VALUE_HPP #define BOOST_LAST_VALUE_HPP #include <cassert> #include <boost/config.hpp> namespace boost { template<typename T> struct last_value { typedef T result_type; template<typename InputIterator> T operator()(InputIterator first, InputIterator last) const { assert(first != last); T value = *first++; while (first != last) value = *first++; return value; } }; template<> struct last_value<void> { #ifdef BOOST_NO_VOID_RETURNS struct unusable {}; public: typedef unusable result_type; #else public: typedef void result_type; #endif // BOOST_NO_VOID_RETURNS template<typename InputIterator> result_type operator()(InputIterator first, InputIterator last) const { while (first != last) *first++; return result_type(); } }; } #endif // BOOST_SIGNALS_LAST_VALUE_HPP