May 2003
Intermediate to advanced
808 pages
32h 24m
English
typeid operator — Runtime type identification operator
postfix-expr := typeid ( expression ) | typeid ( type-id )The typeid operator returns a
const reference to a type_info object that describes type-id or the type of expression. If expression is an lvalue (not a pointer) of
a polymorphic class, the type_info
of the most-derived class is returned. Otherwise, expression is not evaluated, and the
type_info of its static type is
returned.
Each distinct type has its own associated type_info object, but type synonyms (such as
those created with typedef) have
the same type_info object.
template<typename T>
void debug(const T& obj)
{
std::clog <<typeid(obj).name( ) << ':' << &obj << '\n';
}expression, typedef, Chapter 3, <typeinfo>