/*-----------------------------------------------------------------------------+
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Copyright (c) 2010-2011: Joachim Faulhaber
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+------------------------------------------------------------------------------+
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENCE.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt)
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+-----------------------------------------------------------------------------*/
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#ifndef BOOST_ICL_TYPE_TRAITS_INFINITY_HPP_JOFA_100322
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#define BOOST_ICL_TYPE_TRAITS_INFINITY_HPP_JOFA_100322
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#include <string>
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#include <boost/static_assert.hpp>
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#include <boost/icl/type_traits/is_numeric.hpp>
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#include <boost/icl/type_traits/rep_type_of.hpp>
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#include <boost/icl/type_traits/size_type_of.hpp>
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#include <boost/mpl/and.hpp>
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#include <boost/mpl/if.hpp>
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namespace boost{ namespace icl
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{
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template<class Type> struct has_std_infinity
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{
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typedef has_std_infinity type;
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BOOST_STATIC_CONSTANT(bool,
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value = ( is_numeric<Type>::value
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&& std::numeric_limits<Type>::has_infinity
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)
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);
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};
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template<class Type> struct has_max_infinity
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{
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typedef has_max_infinity type;
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BOOST_STATIC_CONSTANT(bool,
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value = ( is_numeric<Type>::value
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&& ! std::numeric_limits<Type>::has_infinity
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)
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);
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};
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//------------------------------------------------------------------------------
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template <class Type, bool has_std_inf=false, bool has_std_max=false>
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struct get_numeric_infinity;
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template <class Type, bool has_std_max>
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struct get_numeric_infinity<Type, true, has_std_max>
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{
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typedef get_numeric_infinity type;
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static Type value()
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{
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return (std::numeric_limits<Type>::infinity)();
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}
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};
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template <class Type>
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struct get_numeric_infinity<Type, false, true>
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{
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typedef get_numeric_infinity type;
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static Type value()
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{
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return (std::numeric_limits<Type>::max)();
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}
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};
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template <class Type>
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struct get_numeric_infinity<Type, false, false>
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{
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typedef get_numeric_infinity type;
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static Type value()
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{
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return Type();
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}
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};
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template <class Type>
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struct numeric_infinity
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{
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typedef numeric_infinity type;
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static Type value()
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{
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return get_numeric_infinity< Type
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, has_std_infinity<Type>::value
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, has_max_infinity<Type>::value >::value();
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}
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};
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//------------------------------------------------------------------------------
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template<class Type, bool has_numeric_inf, bool has_repr_inf, bool has_size, bool has_diff>
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struct get_infinity;
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template<class Type, bool has_repr_inf, bool has_size, bool has_diff>
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struct get_infinity<Type, true, has_repr_inf, has_size, has_diff>
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{
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typedef get_infinity type;
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static Type value()
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{
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return numeric_infinity<Type>::value();
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}
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};
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template<class Type, bool has_size, bool has_diff>
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struct get_infinity<Type, false, true, has_size, has_diff>
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{
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typedef get_infinity type;
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static Type value()
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{
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return Type(numeric_infinity<typename Type::rep>::value());
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}
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};
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template<class Type, bool has_diff>
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struct get_infinity<Type, false, false, true, has_diff>
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{
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typedef get_infinity type;
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typedef typename Type::size_type size_type;
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static Type value()
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{
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return Type(numeric_infinity<size_type>::value());
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}
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};
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template<class Type>
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struct get_infinity<Type, false, false, false, true>
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{
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typedef get_infinity type;
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typedef typename Type::difference_type difference_type;
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static Type value()
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{
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return identity_element<difference_type>::value();
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}
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};
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template<class Type>
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struct get_infinity<Type, false, false, false, false>
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{
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typedef get_infinity type;
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static Type value()
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{
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return identity_element<Type>::value();
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}
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};
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template <class Type> struct infinity
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{
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typedef infinity type;
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static Type value()
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{
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return
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get_infinity< Type
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, is_numeric<Type>::value
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, has_rep_type<Type>::value
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, has_size_type<Type>::value
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, has_difference_type<Type>::value
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>::value();
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}
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};
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template <>
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struct infinity<std::string>
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{
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typedef infinity type;
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static std::string value()
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{
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return std::string();
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}
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};
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}} // namespace boost icl
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#endif
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