| // 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 : std::binary_function<OptionalPointee,OptionalPointee,bool> |
| { |
| 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 : std::binary_function<OptionalPointee,OptionalPointee,bool> |
| { |
| bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const |
| { return less_pointees(x,y) ; } |
| } ; |
| |
| } // namespace boost |
| |
| #endif |
| |