sl@0: // last_value function object (documented as part of Boost.Signals)
sl@0: 
sl@0: // Copyright Douglas Gregor 2001-2003. Use, modification and
sl@0: // distribution is subject to the Boost Software License, Version
sl@0: // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: 
sl@0: // For more information, see http://www.boost.org/libs/signals
sl@0: 
sl@0: #ifndef BOOST_LAST_VALUE_HPP
sl@0: #define BOOST_LAST_VALUE_HPP
sl@0: 
sl@0: #include <cassert>
sl@0: 
sl@0: namespace boost {
sl@0:   template<typename T>
sl@0:   struct last_value {
sl@0:     typedef T result_type;
sl@0: 
sl@0:     template<typename InputIterator>
sl@0:     T operator()(InputIterator first, InputIterator last) const
sl@0:     {
sl@0:       assert(first != last);
sl@0:       T value = *first++;
sl@0:       while (first != last)
sl@0:         value = *first++;
sl@0:       return value;
sl@0:     }
sl@0:   };
sl@0: 
sl@0:   template<>
sl@0:   struct last_value<void> {
sl@0:     struct unusable {};
sl@0: 
sl@0:   public:
sl@0:     typedef unusable result_type;
sl@0: 
sl@0:     template<typename InputIterator>
sl@0:     result_type
sl@0:     operator()(InputIterator first, InputIterator last) const
sl@0:     {
sl@0:       while (first != last)
sl@0:         *first++;
sl@0:       return result_type();
sl@0:     }
sl@0:   };
sl@0: }
sl@0: #endif // BOOST_SIGNALS_LAST_VALUE_HPP