1
0
forked from Alepha/Alepha
Files
Alepha/function_traits.h

85 lines
2.6 KiB
C++

static_assert( __cplusplus > 2020'99 );
#pragma once
#include <Alepha/Alepha.h>
#include <tuple>
#include <type_traits>
#include <functional>
namespace Alepha::Hydrogen ::detail:: function_traits_m
{
inline namespace exports
{
template< typename Function > struct function_traits;
template< typename Function >
using get_args_t= typename function_traits< Function >::args_type;
template< typename Function, int index >
using get_arg_t= std::decay_t< std::tuple_element_t< index, get_args_t< Function > > >;
}
struct nil;
template< bool noexceptness, typename ClassHolder, typename ReturnType, typename ... Args >
struct traits : traits< noexceptness, nil, ReturnType, Args... >
{
using member_type= ReturnType (ClassHolder::*)( Args... );
using const_member_type= ReturnType (ClassHolder::*)( Args... ) const;
};
template< bool noexceptness, typename ReturnType, typename ... Args >
struct traits< noexceptness, nil, ReturnType, Args... >
{
static constexpr bool noexcepted= noexceptness;
using function_type= std::function< ReturnType ( Args... ) noexcept( noexcepted ) >;
using member_type= nil;
using const_member_type= nil;
using args_type= std::tuple< Args... >;
static constexpr std::size_t args_size= sizeof...( Args );
using return_type= ReturnType;
using signature_type= ReturnType( Args... );
};
// General catchall...
template< typename Function >
struct exports::function_traits
: exports::function_traits< std::decay_t< decltype( std::function( std::declval< Function >() ) ) > >
{};
template< typename ReturnType, typename ... Args, bool noexceptness >
struct exports::function_traits< ReturnType ( Args... ) noexcept( noexceptness ) >
: traits< noexceptness, nil, ReturnType, Args... >
{};
template< typename ReturnType, typename ... Args, bool noexceptness >
struct exports::function_traits< ReturnType (*)( Args... ) noexcept( noexceptness ) >
: traits< noexceptness, nil, ReturnType, Args... >
{};
template< typename ReturnType, typename ... Args, bool noexceptness >
struct exports::function_traits< ReturnType (&)( Args... ) noexcept( noexceptness ) >
: traits< noexceptness, nil, ReturnType, Args... >
{};
// The `std::function` form... It also is the catchall for other types...
template< typename ReturnType, typename ... Args, bool noexceptness >
struct exports::function_traits< std::function< ReturnType ( Args... ) noexcept( noexceptness ) > >
: traits< noexceptness, nil, ReturnType, Args... >
{};
}
namespace Alepha::Hydrogen::inline exports::inline function_traits_m
{
using namespace detail::function_traits_m::exports;
}