RTTI Basic Tools

In the following, RTTI-class stands for a C++ class which has RTTI capabilities, p for a pointer to a RTTI-class and T for a C++ RTTI-class. The 'return type' of a macro stands for the type of object that macro expands to.

• typeid STATIC_TYPE_INFO(T): Returns a typeid encoding the type of the C++ RTTI-class T. If T is not a RTTI-class, a compile-time error occurs.
• typeid TYPE_INFO(p): Returns the typeid for the object p is pointing at (regardless of p's own type). If p is not pointing at an object of a RTTI-class, a compile-time error occurs. If p is NULL, a special typeid for the NULL pointer is returned.
• T* PTR_CAST(T,p): Returns the value of pointer p cast to the type T, i.e. a T* or NULL if cast fails. If either *p or T are not RTTI-classes, a compile-time error occurs.
• int typeid::operator==(typeid): Compares two typeids and returns 1 if they represent the same type, else 0. An operator!= with the natural semantics is also provided for typeids.
• const char* typeid::getname(): Returns the textual name of a typeid.
• T* TYPE_NEW(T,typeid t): Given a C++ base type T, an object of type t, where t represents a type identical to or derived from T, is created and returned as a T*. If T is not a RTTI-class a compile-time error occurs. If t is not a type derived from T or not an instantiable type having a default constructor, NULL is returned. The implicit reasons for needing to supply the type T of a baseclass of t are described in detail in Section 5.2.6.