21 lines
916 B
Plaintext
21 lines
916 B
Plaintext
|
This is a base class for implementing virtual base classes (what
|
||
|
|
some people call an abstract class). Kinda kooky. It allows you to
|
||
|
|
explicitly declare what methods are virtual and that must be
|
||
|
|
implemented by subclasses. This might seem silly, since your program
|
||
|
|
will halt and catch fire when an unimplemented virtual method is
|
||
|
|
hit anyway, but there's some benefits.
|
||
|
|
|
||
|
|
The error message is more informative. Instead of the usual "Can't
|
||
|
|
locate object method" error, you'll get one explaining that a virtual
|
||
|
|
method was left unimplemented.
|
||
|
|
|
||
|
|
Subclass authors can explicitly check to make sure they've implemented
|
||
|
|
all the necessary virtual methods. When used as part of a regression
|
||
|
|
test, it will shield against the virtual method requirements changing
|
||
|
|
out from under the subclass.
|
||
|
|
|
||
|
|
Finally, subclass authors can get an explicit list of everything
|
||
|
|
they're expected to implement.
|
||
|
|
|
||
|
|
Doesn't hurt and it doesn't slow you down.
|