Chris@16: /*
Chris@101:  *          Copyright Andrey Semashev 2007 - 2015.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  *    (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  *          http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  */
Chris@16: /*!
Chris@16:  * \file   logical.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   30.03.2008
Chris@16:  *
Chris@16:  * This header contains logical predicates for value comparison, analogous to \c std::less, \c std::greater
Chris@16:  * and others. The main difference from the standard equivalents is that the predicates defined in this
Chris@16:  * header are not templates and therefore do not require a fixed argument type. Furthermore, both arguments
Chris@16:  * may have different types, in which case the comparison is performed without type conversion.
Chris@16:  *
Chris@16:  * \note In case if arguments are integral, the conversion is performed according to the standard C++ rules
Chris@16:  *       in order to avoid warnings from the compiler.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_UTILITY_FUNCTIONAL_LOGICAL_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_UTILITY_FUNCTIONAL_LOGICAL_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/and.hpp>
Chris@16: #include <boost/type_traits/is_integral.hpp>
Chris@16: #include <boost/type_traits/is_unsigned.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: //! The trait creates a common integral type suitable for comparison. This is mostly to silence compiler warnings like 'signed/unsigned mismatch'.
Chris@16: template< typename T, typename U, unsigned int TSizeV = sizeof(T), unsigned int USizeV = sizeof(U), bool TSmallerThanU = (sizeof(T) < sizeof(U)) >
Chris@16: struct make_common_integral_type
Chris@16: {
Chris@16:     typedef T type;
Chris@16: };
Chris@16: 
Chris@16: //! Specialization for case when \c T is smaller than \c U
Chris@16: template< typename T, typename U, unsigned int TSizeV, unsigned int USizeV >
Chris@16: struct make_common_integral_type< T, U, TSizeV, USizeV, true >
Chris@16: {
Chris@16:     typedef U type;
Chris@16: };
Chris@16: 
Chris@16: //! Specialization for the case when both types have the same size
Chris@16: template< typename T, typename U, unsigned int SizeV >
Chris@16: struct make_common_integral_type< T, U, SizeV, SizeV, false > :
Chris@16:     public mpl::if_<
Chris@16:         is_unsigned< T >,
Chris@16:         T,
Chris@16:         U
Chris@16:     >
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: //! Equality predicate
Chris@16: struct equal_to
Chris@16: {
Chris@16:     typedef bool result_type;
Chris@16: 
Chris@16:     template< typename T, typename U >
Chris@16:     bool operator() (T const& left, U const& right) const
Chris@16:     {
Chris@16:         return op(left, right, typename mpl::and_< is_integral< T >, is_integral< U > >::type());
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::false_ const&)
Chris@16:     {
Chris@16:         return (left == right);
Chris@16:     }
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::true_ const&)
Chris@16:     {
Chris@16:         typedef typename aux::make_common_integral_type< T, U >::type common_integral_type;
Chris@16:         return static_cast< common_integral_type >(left) == static_cast< common_integral_type >(right);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! Inequality predicate
Chris@16: struct not_equal_to
Chris@16: {
Chris@16:     typedef bool result_type;
Chris@16: 
Chris@16:     template< typename T, typename U >
Chris@16:     bool operator() (T const& left, U const& right) const
Chris@16:     {
Chris@16:         return op(left, right, typename mpl::and_< is_integral< T >, is_integral< U > >::type());
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::false_ const&)
Chris@16:     {
Chris@16:         return (left != right);
Chris@16:     }
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::true_ const&)
Chris@16:     {
Chris@16:         typedef typename aux::make_common_integral_type< T, U >::type common_integral_type;
Chris@16:         return static_cast< common_integral_type >(left) != static_cast< common_integral_type >(right);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! Less predicate
Chris@16: struct less
Chris@16: {
Chris@16:     typedef bool result_type;
Chris@16: 
Chris@16:     template< typename T, typename U >
Chris@16:     bool operator() (T const& left, U const& right) const
Chris@16:     {
Chris@16:         return op(left, right, typename mpl::and_< is_integral< T >, is_integral< U > >::type());
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::false_ const&)
Chris@16:     {
Chris@16:         return (left < right);
Chris@16:     }
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::true_ const&)
Chris@16:     {
Chris@16:         typedef typename aux::make_common_integral_type< T, U >::type common_integral_type;
Chris@16:         return static_cast< common_integral_type >(left) < static_cast< common_integral_type >(right);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! Greater predicate
Chris@16: struct greater
Chris@16: {
Chris@16:     typedef bool result_type;
Chris@16: 
Chris@16:     template< typename T, typename U >
Chris@16:     bool operator() (T const& left, U const& right) const
Chris@16:     {
Chris@16:         return op(left, right, typename mpl::and_< is_integral< T >, is_integral< U > >::type());
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::false_ const&)
Chris@16:     {
Chris@16:         return (left > right);
Chris@16:     }
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::true_ const&)
Chris@16:     {
Chris@16:         typedef typename aux::make_common_integral_type< T, U >::type common_integral_type;
Chris@16:         return static_cast< common_integral_type >(left) > static_cast< common_integral_type >(right);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! Less or equal predicate
Chris@16: struct less_equal
Chris@16: {
Chris@16:     typedef bool result_type;
Chris@16: 
Chris@16:     template< typename T, typename U >
Chris@16:     bool operator() (T const& left, U const& right) const
Chris@16:     {
Chris@16:         return op(left, right, typename mpl::and_< is_integral< T >, is_integral< U > >::type());
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::false_ const&)
Chris@16:     {
Chris@16:         return (left <= right);
Chris@16:     }
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::true_ const&)
Chris@16:     {
Chris@16:         typedef typename aux::make_common_integral_type< T, U >::type common_integral_type;
Chris@16:         return static_cast< common_integral_type >(left) <= static_cast< common_integral_type >(right);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //! Greater or equal predicate
Chris@16: struct greater_equal
Chris@16: {
Chris@16:     typedef bool result_type;
Chris@16: 
Chris@16:     template< typename T, typename U >
Chris@16:     bool operator() (T const& left, U const& right) const
Chris@16:     {
Chris@16:         return op(left, right, typename mpl::and_< is_integral< T >, is_integral< U > >::type());
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::false_ const&)
Chris@16:     {
Chris@16:         return (left >= right);
Chris@16:     }
Chris@16:     template< typename T, typename U >
Chris@16:     static bool op(T const& left, U const& right, mpl::true_ const&)
Chris@16:     {
Chris@16:         typedef typename aux::make_common_integral_type< T, U >::type common_integral_type;
Chris@16:         return static_cast< common_integral_type >(left) >= static_cast< common_integral_type >(right);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #endif // BOOST_LOG_UTILITY_FUNCTIONAL_LOGICAL_HPP_INCLUDED_