123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107 |
- #ifndef BOOST_TYPE_TRAITS_DETAIL_COMMON_TYPE_IMPL_HPP_INCLUDED
- #define BOOST_TYPE_TRAITS_DETAIL_COMMON_TYPE_IMPL_HPP_INCLUDED
- //
- // Copyright 2015 Peter Dimov
- //
- // Distributed under 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
- //
- #include <boost/type_traits/detail/common_arithmetic_type.hpp>
- #include <boost/type_traits/detail/composite_pointer_type.hpp>
- #include <boost/type_traits/detail/composite_member_pointer_type.hpp>
- #include <boost/type_traits/type_identity.hpp>
- #include <boost/type_traits/is_class.hpp>
- #include <boost/type_traits/is_union.hpp>
- #include <boost/type_traits/is_convertible.hpp>
- #include <boost/type_traits/is_pointer.hpp>
- #include <boost/type_traits/is_member_pointer.hpp>
- #include <boost/type_traits/conditional.hpp>
- namespace boost
- {
- namespace type_traits_detail
- {
- // the arguments to common_type_impl have already been passed through decay<>
- template<class T, class U> struct common_type_impl;
- // same type
- template<class T> struct common_type_impl<T, T>
- {
- typedef T type;
- };
- // one of the operands is a class type, try conversions in both directions
- template<class T, class U> struct ct_class
- {
- BOOST_STATIC_CONSTANT( bool, ct = boost::is_class<T>::value || boost::is_union<T>::value );
- BOOST_STATIC_CONSTANT( bool, cu = boost::is_class<U>::value || boost::is_union<U>::value );
- BOOST_STATIC_CONSTANT( bool, value = ct || cu );
- };
- template<class T, class U> struct common_type_impl3;
- template<class T, class U> struct common_type_class: public boost::conditional<
- boost::is_convertible<T, U>::value && !boost::is_convertible<U, T>::value,
- boost::type_identity<U>,
- typename boost::conditional<
- boost::is_convertible<U, T>::value && !boost::is_convertible<T, U>::value,
- boost::type_identity<T>,
- common_type_impl3<T, U>
- >::type
- >::type
- {
- };
- template<class T, class U> struct common_type_impl: public boost::conditional<
- ct_class<T, U>::value,
- common_type_class<T, U>,
- common_type_impl3<T, U> >::type
- {
- };
- // pointers
- template<class T, class U> struct common_type_impl4;
- template<class T, class U> struct common_type_impl3: public boost::conditional<
- boost::is_pointer<T>::value || boost::is_pointer<U>::value,
- composite_pointer_type<T, U>,
- common_type_impl4<T, U> >::type
- {
- };
- // pointers to members
- template<class T, class U> struct common_type_impl5;
- template<class T, class U> struct common_type_impl4: public boost::conditional<
- boost::is_member_pointer<T>::value || boost::is_member_pointer<U>::value,
- composite_member_pointer_type<T, U>,
- common_type_impl5<T, U> >::type
- {
- };
- // arithmetic types (including class types w/ conversions to arithmetic and enums)
- template<class T, class U> struct common_type_impl5: public common_arithmetic_type<T, U>
- {
- };
- } // namespace type_traits_detail
- } // namespace boost
- #endif // #ifndef BOOST_TYPE_TRAITS_DETAIL_COMMON_TYPE_IMPL_HPP_INCLUDED
|