get type of variable

type.cpp

#include <iostream>
#include <string_view>


template <class T>
constexpr std::string_view type_name()
{
    using namespace std;
    #ifdef __clang__
    string_view p = __PRETTY_FUNCTION__;
    return string_view(p.data() + 34, p.size() - 34 - 1);
    #elif defined(__GNUC__)
    string_view p = __PRETTY_FUNCTION__;
    #  if __cplusplus < 201402
    return string_view(p.data() + 36, p.size() - 36 - 1);
    #  else
    return string_view(p.data() + 49, p.find(';', 49) - 49);
    #  endif
    #elif defined(_MSC_VER)
    string_view p = __FUNCSIG__;
    return string_view(p.data() + 84, p.size() - 84 - 7);
    #endif
}

enum class Foo
{
    foo1,
    foo2
};

int main()
{
    auto a = Foo::foo1;
    auto&& b = static_cast<int&&>(3);
    std::cout << type_name<decltype(a)>() << "\n";
    std::cout << type_name<decltype(b)>() << "\n";

    return 0;
}