On 03/15/2011 12:54 PM, Daniel Gibson wrote:
> Furthermore I find C++'s class handling quite unfortunate.. only having
> polymorphism when explicitly using pointers really sucks.
> e.g. you have a base class Foo and a class Bar derived from Foo.. now
you wanna
> put Objects of type Foo and Bar in a list.. what do you do?
> list<Foo>? won't work for Bar Objects. So you gotta use list<Foo*>.
> Using list<Foo*> really sucks, especially with iterators.. you end
up using
> something like
> list<Foo*>::iterator it = ... ;
> (*it)->x = 3;
> int bla = (*it)->myFun(42);
>
> Now *that* is ugly.
I am changing the topic here a little but C++ has more problems as
witnessed in the above code. Normally the objects in the list are
created by 'new', and not exception-safe for that reason to be left
naked in a list.
A safe idiom is to use a copyable smart pointer, e.g.
list<shared_ptr<Foo> >::iterator it = ...;
D's classes' being reference types and its garbage collector help a lot
in that regard:
list!Foo myList; // can hold Bars too
But that's a different topic... :)
Ali
