dynamic_cast operator — Polymorphic cast of class type objects
postfix-expr := dynamic_cast < type-id > ( expression )
The dynamic_cast
operator
performs a polymorphic cast on a pointer or reference to an object
of class type. If expression
is a
pointer or reference to a base class, type-id
can be a pointer or reference to a
derived class. If the dynamic type of the object is not that of
type-id
or a class derived from
type-id
, the cast fails. If
expression
is a pointer, failure
returns a null pointer; if expression is a
reference, failure throws std::bad_cast
. Casts from a derived to an
unambiguous, accessible base class always succeed.
If expression
is a null
pointer, the result is a null pointer. If type-id
is a pointer to void
, the cast succeeds and returns a
pointer to the most-derived object that expression
represents.