// Copyright (C) 2003, Fernando Luis Cacciola Carballal. // // 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) // // See http://www.boost.org/libs/optional for documentation. // // You are welcome to contact the author at: // fernando_cacciola@hotmail.com // #ifndef BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP #define BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP #include<functional> namespace boost { // template<class OP> bool equal_pointees(OP const& x, OP const& y); // template<class OP> struct equal_pointees_t; // // Being OP a model of OptionalPointee (either a pointer or an optional): // // If both x and y have valid pointees, returns the result of (*x == *y) // If only one has a valid pointee, returns false. // If none have valid pointees, returns true. // No-throw template<class OptionalPointee> inline bool equal_pointees ( OptionalPointee const& x, OptionalPointee const& y ) { return (!x) != (!y) ? false : ( !x ? true : (*x) == (*y) ) ; } template<class OptionalPointee> struct equal_pointees_t { typedef bool result_type; typedef OptionalPointee first_argument_type; typedef OptionalPointee second_argument_type; bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const { return equal_pointees(x,y) ; } } ; // template<class OP> bool less_pointees(OP const& x, OP const& y); // template<class OP> struct less_pointees_t; // // Being OP a model of OptionalPointee (either a pointer or an optional): // // If y has not a valid pointee, returns false. // ElseIf x has not a valid pointee, returns true. // ElseIf both x and y have valid pointees, returns the result of (*x < *y) // No-throw template<class OptionalPointee> inline bool less_pointees ( OptionalPointee const& x, OptionalPointee const& y ) { return !y ? false : ( !x ? true : (*x) < (*y) ) ; } template<class OptionalPointee> struct less_pointees_t { typedef bool result_type; typedef OptionalPointee first_argument_type; typedef OptionalPointee second_argument_type; bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const { return less_pointees(x,y) ; } } ; } // namespace boost #endif