C++ provides an operator called typeid that will return type information about a variable (or a type) at runtime. Runtime Type Information (RTTI) is significant when you use custom types that can be used in a polymorphic way; details will be left until later chapters. RTTI allows you to check at runtime the type of a variable and process the variable accordingly. RTTI is returned through a type_info object (in the <typeinfo> header file):
cout << "int type name: " << typeid(int).name() << endl; int i = 42; cout << "i type name: " << typeid(i).name() << endl;
In both cases, you'll see int printed as the type. The type_info class defines comparison operators (== and !=) so you can compare types:
auto ...
