libcarla/include/system/boost/callable_traits/detail/forward_declarations.hpp
2024-10-18 13:19:59 +08:00

55 lines
1.4 KiB
C++

#ifndef BOOST_CLBL_TRTS_DETAIL_FORWARD_DECLARATIONS
#define BOOST_CLBL_TRTS_DETAIL_FORWARD_DECLARATIONS
#include <boost/callable_traits/detail/config.hpp>
#include <boost/callable_traits/detail/default_callable_traits.hpp>
namespace boost { namespace callable_traits { namespace detail {
template<typename T>
struct function;
template<typename T>
struct has_normal_call_operator
{
template<typename N, N Value>
struct check { check(std::nullptr_t) {} };
template<typename U>
static std::int8_t test(
check<decltype(&U::operator()), &U::operator()>);
template<typename>
static std::int16_t test(...);
static constexpr bool value =
sizeof(test<T>(nullptr)) == sizeof(std::int8_t);
};
struct callable_dummy {
void operator()() {}
};
template<typename T>
using default_to_function_object = typename std::conditional<
has_normal_call_operator<T>::value,
T, callable_dummy>::type;
template<typename T>
struct pmf;
template<typename T>
struct pmd;
template<typename F, typename T = typename std::remove_reference<F>::type>
using function_object_base = typename std::conditional<
has_normal_call_operator<T>::value,
pmf<decltype(&default_to_function_object<T>::operator())>,
default_callable_traits<T>>::type;
template<typename T, typename Base = function_object_base<T>>
struct function_object;
}}} // namespace boost::callable_traits::detail
#endif // #ifndef BOOST_CLBL_TRTS_DETAIL_FORWARD_DECLARATIONS