Is it possible to print a variable's type in standard C++?

Question

For example:

int a = 12;
cout << typeof(a) << endl;

Expected output:

int

Answer 1

Copying from this answer: https://stackoverflow.com/a/56766138/11502722

I was able to get this somewhat working for C++ static_assert(). The wrinkle here is that static_assert() only accepts string literals; constexpr string_view will not work. You will need to accept extra text around the typename, but it works:

template
constexpr void assertIfTestFailed()
{
#ifdef __clang__
    static_assert(testFn(), "Test failed on this used type: " __PRETTY_FUNCTION__);
#elif defined(__GNUC__)
    static_assert(testFn(), "Test failed on this used type: " __PRETTY_FUNCTION__);
#elif defined(_MSC_VER)
    static_assert(testFn(), "Test failed on this used type: " __FUNCSIG__);
#else
    static_assert(testFn(), "Test failed on this used type (see surrounding logged error for details).");
#endif
    }
}

MSVC Output:

error C2338: Test failed on this used type: void __cdecl assertIfTestFailed(void)
... continued trace of where the erroring code came from ...