boost/type_traits/has_plus_assign.hpp
// (C) Copyright 2009-2011 Frederic Bron.
//
// Use, modification and distribution are subject to 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).
//
// See http://www.boost.org/libs/type_traits for most recent version including documentation.
#ifndef BOOST_TT_HAS_PLUS_ASSIGN_HPP_INCLUDED
#define BOOST_TT_HAS_PLUS_ASSIGN_HPP_INCLUDED
#include <boost/config.hpp>
#include <boost/type_traits/detail/config.hpp>
// cannot include this header without getting warnings of the kind:
// gcc:
// warning: value computed is not used
// warning: comparison between signed and unsigned integer expressions
// msvc:
// warning C4018: '<' : signed/unsigned mismatch
// warning C4244: '+=' : conversion from 'double' to 'char', possible loss of data
// warning C4547: '*' : operator before comma has no effect; expected operator with side-effect
// warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning)
// warning C4804: '<' : unsafe use of type 'bool' in operation
// warning C4805: '==' : unsafe mix of type 'bool' and type 'char' in operation
// cannot find another implementation -> declared as system header to suppress these warnings.
#if defined(__GNUC__)
# pragma GCC system_header
#elif defined(BOOST_MSVC)
# pragma warning ( push )
# pragma warning ( disable : 4018 4244 4547 4800 4804 4805 4913 4133)
# if BOOST_WORKAROUND(BOOST_MSVC_FULL_VER, >= 140050000)
# pragma warning ( disable : 6334)
# endif
#endif
#if defined(BOOST_TT_HAS_ACCURATE_BINARY_OPERATOR_DETECTION)
#include <boost/type_traits/integral_constant.hpp>
#include <boost/type_traits/make_void.hpp>
#include <boost/type_traits/is_convertible.hpp>
#include <boost/type_traits/is_void.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/type_traits/is_pointer.hpp>
#include <boost/type_traits/is_arithmetic.hpp>
#include <boost/type_traits/add_reference.hpp>
#include <boost/type_traits/remove_pointer.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <utility>
namespace boost
{
namespace binary_op_detail {
struct dont_care;
template <class T, class U, class Ret, class = void>
struct has_plus_assign_ret_imp : public boost::false_type {};
template <class T, class U, class Ret>
struct has_plus_assign_ret_imp<T, U, Ret, typename boost::make_void<decltype(std::declval<typename add_reference<T>::type>() += std::declval<typename add_reference<U>::type>())>::type>
: public boost::integral_constant<bool, ::boost::is_convertible<decltype(std::declval<typename add_reference<T>::type>() += std::declval<typename add_reference<U>::type>()), Ret>::value> {};
template <class T, class U, class = void >
struct has_plus_assign_void_imp : public boost::false_type {};
template <class T, class U>
struct has_plus_assign_void_imp<T, U, typename boost::make_void<decltype(std::declval<typename add_reference<T>::type>() += std::declval<typename add_reference<U>::type>())>::type>
: public boost::integral_constant<bool, ::boost::is_void<decltype(std::declval<typename add_reference<T>::type>() += std::declval<typename add_reference<U>::type>())>::value> {};
template <class T, class U, class = void>
struct has_plus_assign_dc_imp : public boost::false_type {};
template <class T, class U>
struct has_plus_assign_dc_imp<T, U, typename boost::make_void<decltype(std::declval<typename add_reference<T>::type>() += std::declval<typename add_reference<U>::type>())>::type>
: public boost::true_type {};
template <class T, class U, class Ret>
struct has_plus_assign_filter_ret : public boost::binary_op_detail:: has_plus_assign_ret_imp <T, U, Ret> {};
template <class T, class U>
struct has_plus_assign_filter_ret<T, U, void> : public boost::binary_op_detail:: has_plus_assign_void_imp <T, U> {};
template <class T, class U>
struct has_plus_assign_filter_ret<T, U, boost::binary_op_detail::dont_care> : public boost::binary_op_detail:: has_plus_assign_dc_imp <T, U> {};
template <class T, class U, class Ret, bool f>
struct has_plus_assign_filter_impossible : public boost::binary_op_detail:: has_plus_assign_filter_ret <T, U, Ret> {};
template <class T, class U, class Ret>
struct has_plus_assign_filter_impossible<T, U, Ret, true> : public boost::false_type {};
}
template <class T, class U = T, class Ret = boost::binary_op_detail::dont_care>
struct has_plus_assign : public boost::binary_op_detail:: has_plus_assign_filter_impossible <T, U, Ret, boost::is_arithmetic<typename boost::remove_reference<T>::type>::value && boost::is_pointer<typename remove_reference<U>::type>::value && !boost::is_same<bool, typename boost::remove_cv<typename remove_reference<T>::type>::type>::value> {};
}
#else
#define BOOST_TT_TRAIT_NAME has_plus_assign
#define BOOST_TT_TRAIT_OP +=
#define BOOST_TT_FORBIDDEN_IF\
(\
/* Lhs==pointer and Rhs==pointer */\
(\
::boost::is_pointer< Lhs_noref >::value && \
::boost::is_pointer< Rhs_noref >::value\
) || \
/* Lhs==void* and Rhs==fundamental */\
(\
::boost::is_pointer< Lhs_noref >::value && \
::boost::is_void< Lhs_noptr >::value && \
::boost::is_fundamental< Rhs_nocv >::value\
) || \
/* Rhs==void* and Lhs==fundamental */\
(\
::boost::is_pointer< Rhs_noref >::value && \
::boost::is_void< Rhs_noptr >::value && \
::boost::is_fundamental< Lhs_nocv >::value\
) || \
/* Lhs==pointer and Rhs==fundamental and Rhs!=integral */\
(\
::boost::is_pointer< Lhs_noref >::value && \
::boost::is_fundamental< Rhs_nocv >::value && \
(! ::boost::is_integral< Rhs_noref >::value )\
) || \
/* Rhs==pointer and Lhs==fundamental and Lhs!=bool */\
(\
::boost::is_pointer< Rhs_noref >::value && \
::boost::is_fundamental< Lhs_nocv >::value && \
(! ::boost::is_same< Lhs_nocv, bool >::value )\
) || \
/* (Lhs==fundamental or Lhs==pointer) and (Rhs==fundamental or Rhs==pointer) and (Lhs==const) */\
(\
(\
::boost::is_fundamental< Lhs_nocv >::value || \
::boost::is_pointer< Lhs_noref >::value\
) && \
( \
::boost::is_fundamental< Rhs_nocv >::value || \
::boost::is_pointer< Rhs_noref >::value\
) && \
::boost::is_const< Lhs_noref >::value\
)\
)
#include <boost/type_traits/detail/has_binary_operator.hpp>
#undef BOOST_TT_TRAIT_NAME
#undef BOOST_TT_TRAIT_OP
#undef BOOST_TT_FORBIDDEN_IF
#endif
#if defined(BOOST_MSVC)
# pragma warning (pop)
#endif
#endif