Print types of variables at runtime c++

test.cpp

#include <type_name.h>
#include <iostream>

class A {
  public:
    int a = 1;
    int b = 2;
    int c = 3;
};


int main() {
    A test{};
    A& test_ref = test;
    A* test_ptr = &test;
    auto auto_ref = test_ref;
    const auto& auto_ref2 = test_ref;
    auto& auto_ref3 = test;

    std::cout << type_name<decltype(test)>() << std::endl;
    std::cout << type_name<decltype(test_ptr)>() << std::endl;
    std::cout << type_name<decltype(test_ref)>() << std::endl;
    std::cout << type_name<decltype(auto_ref)>() << std::endl;
    std::cout << type_name<decltype(auto_ref2)>() << std::endl;
    std::cout << type_name<decltype(auto_ref3)>() << std::endl;
}

type_name.h

#include <memory>
#include <string>
#include <cxxabi.h>

template <class T>
std::string
type_name()
{
    typedef typename std::remove_reference<T>::type TR;
    std::unique_ptr<char, void(*)(void*)> own
           (
#ifndef _MSC_VER
                abi::__cxa_demangle(typeid(TR).name(), nullptr,
                                           nullptr, nullptr),
#else
                nullptr,
#endif
                std::free
           );
    std::string r = own != nullptr ? own.get() : typeid(TR).name();
    if (std::is_const<TR>::value)
        r += " const";
    if (std::is_volatile<TR>::value)
        r += " volatile";
    if (std::is_lvalue_reference<T>::value)
        r += "&";
    else if (std::is_rvalue_reference<T>::value)
        r += "&&";
    return r;
}

https://godbolt.org/z/W4aYTf4Pe

Result:

A*
A&
A
A const&
A&