| || |
Run-time Type Identification, or RTTI, is a mechanism for interrogating the type of an object at runtime. Such a mechanism is useful for avoiding the dreaded switch-on-type technique used before RTTI was incorporated into the language. Until recently, some C++ compilers did not support RTTI, so it is necessary to assume that it may not be widely available.
Switch-on-type involves giving all classes a method that returns a special type token that an object can use to discover its own type. For example:
Although switch-on-type is not elegant, RTTI isn't particularly object-oriented either. Given the limited number of times you ought to be using RTTI, the switch-on-type technique may be reasonable.