C++ typedef args to typeid list

typdef_args_to_typeids

#include <iostream>
#include <typeinfo>
#include <typeindex>
#include <span>

typedef int (*tExample) (int a, bool b, char* c, long long d);

template<typename T>
struct arg_types {};

template<typename R, typename... A>
struct arg_types<R(*)(A...)> {
    inline static const std::type_index value[] = {typeid(A)...};
};

template<typename T>
static constexpr std::span<const std::type_index> arg_types_v = arg_types<T>::value;

int main()
{
    auto vec = arg_types_v<tExample>;
    for (const auto& t : vec)
    {
        std::cout << t.hash_code() << std::endl;
    }
}