diff options
Diffstat (limited to 'boost/type_traits/has_minus.hpp')
-rw-r--r-- | boost/type_traits/has_minus.hpp | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/boost/type_traits/has_minus.hpp b/boost/type_traits/has_minus.hpp index 5e13c16014..ba47253ad0 100644 --- a/boost/type_traits/has_minus.hpp +++ b/boost/type_traits/has_minus.hpp @@ -9,6 +9,97 @@ #ifndef BOOST_TT_HAS_MINUS_HPP_INCLUDED #define BOOST_TT_HAS_MINUS_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/add_reference.hpp> +#include <boost/type_traits/remove_pointer.hpp> +#include <boost/type_traits/remove_reference.hpp> +#include <utility> + +namespace boost +{ + + namespace binary_op_detail { + + struct dont_care; + + template <class T, class U, class Ret, class = boost::void_t<>> + struct has_minus_ret_imp : public boost::false_type {}; + + template <class T, class U, class Ret> + struct has_minus_ret_imp<T, U, Ret, boost::void_t<decltype(std::declval<typename add_reference<T>::type>() - std::declval<typename add_reference<U>::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 = boost::void_t<> > + struct has_minus_void_imp : public boost::false_type {}; + + template <class T, class U> + struct has_minus_void_imp<T, U, boost::void_t<decltype(std::declval<typename add_reference<T>::type>() - std::declval<typename add_reference<U>::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 = boost::void_t<>> + struct has_minus_dc_imp : public boost::false_type {}; + + template <class T, class U> + struct has_minus_dc_imp<T, U, boost::void_t<decltype(std::declval<typename add_reference<T>::type>() - std::declval<typename add_reference<U>::type>())> > + : public boost::true_type {}; + + template <class T, class U, class Ret> + struct has_minus_ret_filter : public boost::binary_op_detail::has_minus_ret_imp <T, U, Ret> {}; + template <class T, class U> + struct has_minus_ret_filter<T, U, void> : public boost::binary_op_detail::has_minus_void_imp <T, U> {}; + template <class T, class U> + struct has_minus_ret_filter<T, U, boost::binary_op_detail::dont_care> : public boost::binary_op_detail::has_minus_dc_imp <T, U> {}; + + template <class T, class U, class Ret, bool b> + struct has_minus_void_ptr_filter : public boost::binary_op_detail::has_minus_ret_filter <T, U, Ret> {}; + template <class T, class U, class Ret> + struct has_minus_void_ptr_filter<T, U, Ret, true> : public boost::false_type {}; + + } + + template <class T, class U = T, class Ret = boost::binary_op_detail::dont_care> + struct has_minus : + public boost::binary_op_detail::has_minus_void_ptr_filter< + T, U, Ret, + boost::is_void<typename remove_pointer<typename remove_reference<T>::type>::type>::value + || boost::is_void<typename remove_pointer<typename remove_reference<U>::type>::type>::value> {}; + + +} + +#else + + #define BOOST_TT_TRAIT_NAME has_minus #define BOOST_TT_TRAIT_OP - #define BOOST_TT_FORBIDDEN_IF\ @@ -50,6 +141,7 @@ )\ ) +#define BOOST_TT_FORBIDDEN_IF_NEW (boost::is_void<typename remove_pointer<typename boost::remove_reference<T>::type>::type>::value || boost::is_void<typename remove_pointer<typename boost::remove_reference<U>::type>::type>::value) #include <boost/type_traits/detail/has_binary_operator.hpp> @@ -58,3 +150,4 @@ #undef BOOST_TT_FORBIDDEN_IF #endif +#endif |