Resolving template member function overload

Question

I'm trying to write template class that inherits from T and to correctly implement one part, I need to know what data type is this T working with. Fortunately, all valid substitutions for T have member method GetOutput which returns the expected data type. However, the method have two overloads: GetOutput() and GetOutput(int) . I was trying to extract the type using this answer but am failing to get the overload resolution working:

using OutputType = typename std::result_of<decltype(&T::GetOutput)(T)>::type;

Is what I'm trying possible and if so, what is the correct way to get there?

Answer 1

如果GetOutput的两个重载返回相同的类型，您可以只选择其中之一并使用其返回类型：

using OutputType = decltype(std::declval<T&>().GetOutput());