| 1 | // Copyright (C) 2003, Fernando Luis Cacciola Carballal. |
|---|
| 2 | // |
|---|
| 3 | // Use, modification, and distribution is subject to the Boost Software |
|---|
| 4 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
|---|
| 5 | // http://www.boost.org/LICENSE_1_0.txt) |
|---|
| 6 | // |
|---|
| 7 | // See http://www.boost.org/libs/optional for documentation. |
|---|
| 8 | // |
|---|
| 9 | // You are welcome to contact the author at: |
|---|
| 10 | // fernando_cacciola@hotmail.com |
|---|
| 11 | // |
|---|
| 12 | #ifndef BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP |
|---|
| 13 | #define BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP |
|---|
| 14 | |
|---|
| 15 | #include<functional> |
|---|
| 16 | |
|---|
| 17 | namespace boost { |
|---|
| 18 | |
|---|
| 19 | // template<class OP> bool equal_pointees(OP const& x, OP const& y); |
|---|
| 20 | // template<class OP> struct equal_pointees_t; |
|---|
| 21 | // |
|---|
| 22 | // Being OP a model of OptionalPointee (either a pointer or an optional): |
|---|
| 23 | // |
|---|
| 24 | // If both x and y have valid pointees, returns the result of (*x == *y) |
|---|
| 25 | // If only one has a valid pointee, returns false. |
|---|
| 26 | // If none have valid pointees, returns true. |
|---|
| 27 | // No-throw |
|---|
| 28 | template<class OptionalPointee> |
|---|
| 29 | inline |
|---|
| 30 | bool equal_pointees ( OptionalPointee const& x, OptionalPointee const& y ) |
|---|
| 31 | { |
|---|
| 32 | return (!x) != (!y) ? false : ( !x ? true : (*x) == (*y) ) ; |
|---|
| 33 | } |
|---|
| 34 | |
|---|
| 35 | template<class OptionalPointee> |
|---|
| 36 | struct equal_pointees_t : std::binary_function<OptionalPointee,OptionalPointee,bool> |
|---|
| 37 | { |
|---|
| 38 | bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const |
|---|
| 39 | { return equal_pointees(x,y) ; } |
|---|
| 40 | } ; |
|---|
| 41 | |
|---|
| 42 | // template<class OP> bool less_pointees(OP const& x, OP const& y); |
|---|
| 43 | // template<class OP> struct less_pointees_t; |
|---|
| 44 | // |
|---|
| 45 | // Being OP a model of OptionalPointee (either a pointer or an optional): |
|---|
| 46 | // |
|---|
| 47 | // If y has not a valid pointee, returns false. |
|---|
| 48 | // ElseIf x has not a valid pointee, returns true. |
|---|
| 49 | // ElseIf both x and y have valid pointees, returns the result of (*x < *y) |
|---|
| 50 | // No-throw |
|---|
| 51 | template<class OptionalPointee> |
|---|
| 52 | inline |
|---|
| 53 | bool less_pointees ( OptionalPointee const& x, OptionalPointee const& y ) |
|---|
| 54 | { |
|---|
| 55 | return !y ? false : ( !x ? true : (*x) < (*y) ) ; |
|---|
| 56 | } |
|---|
| 57 | |
|---|
| 58 | template<class OptionalPointee> |
|---|
| 59 | struct less_pointees_t : std::binary_function<OptionalPointee,OptionalPointee,bool> |
|---|
| 60 | { |
|---|
| 61 | bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const |
|---|
| 62 | { return less_pointees(x,y) ; } |
|---|
| 63 | } ; |
|---|
| 64 | |
|---|
| 65 | } // namespace boost |
|---|
| 66 | |
|---|
| 67 | #endif |
|---|
| 68 | |
|---|
| 69 | |
|---|
