"Justin Johansson" <n...@spam.com> wrote in message
news:hiktil$20a...@digitalmars.com...
> Happy New Year 2010 Everybody.
>
> Having resumed C++ nationality for the last few months, I kind of miss D's
> auto keyword.
>
> I am wondering, though, from an OO/polymorphism perspective, and UML and
> sound software engineering perspective as well, what does D's auto keyword
> buy you except (perhaps) laziness (in keystrokes)?
>
It makes it possible to have one variable's type match that of another
variable without having to update as many places when you want to change.
Ex:
---------------
class Foo {
wchar x;
void bar() {
wchar[] y = x ~ "stuff";
wchar[] z = y ~ x;
}
}
---------------
Now if I decide I want 'x' to be a 'char', I have to remember to change
'wchar'->'char' in all three declarations. But if 'y' and 'z' are declared
with auto, all I have to do is change the declaration of 'x'. You could also
get the same effect with typeof(), but that's more verbose and less DRY.
