77 lines
2.3 KiB
C++
77 lines
2.3 KiB
C++
// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
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//
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// Use, modification, and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/optional for documentation.
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//
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// You are welcome to contact the author at:
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// fernando_cacciola@hotmail.com
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//
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#ifndef BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP
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#define BOOST_UTILITY_COMPARE_POINTEES_25AGO2003_HPP
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#include<functional>
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namespace boost {
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// template<class OP> bool equal_pointees(OP const& x, OP const& y);
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// template<class OP> struct equal_pointees_t;
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//
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// Being OP a model of OptionalPointee (either a pointer or an optional):
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//
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// If both x and y have valid pointees, returns the result of (*x == *y)
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// If only one has a valid pointee, returns false.
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// If none have valid pointees, returns true.
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// No-throw
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template<class OptionalPointee>
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inline
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bool equal_pointees ( OptionalPointee const& x, OptionalPointee const& y )
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{
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return (!x) != (!y) ? false : ( !x ? true : (*x) == (*y) ) ;
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}
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template<class OptionalPointee>
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struct equal_pointees_t
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{
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typedef bool result_type;
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typedef OptionalPointee first_argument_type;
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typedef OptionalPointee second_argument_type;
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bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const
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{ return equal_pointees(x,y) ; }
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} ;
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// template<class OP> bool less_pointees(OP const& x, OP const& y);
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// template<class OP> struct less_pointees_t;
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//
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// Being OP a model of OptionalPointee (either a pointer or an optional):
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//
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// If y has not a valid pointee, returns false.
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// ElseIf x has not a valid pointee, returns true.
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// ElseIf both x and y have valid pointees, returns the result of (*x < *y)
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// No-throw
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template<class OptionalPointee>
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inline
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bool less_pointees ( OptionalPointee const& x, OptionalPointee const& y )
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{
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return !y ? false : ( !x ? true : (*x) < (*y) ) ;
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}
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template<class OptionalPointee>
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struct less_pointees_t
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{
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typedef bool result_type;
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typedef OptionalPointee first_argument_type;
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typedef OptionalPointee second_argument_type;
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bool operator() ( OptionalPointee const& x, OptionalPointee const& y ) const
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{ return less_pointees(x,y) ; }
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} ;
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} // namespace boost
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#endif
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