"with" should be deprecated with extreme prejudice

[Andrei Alexandrescu]

Bill Baxter wrote:
> On Mon, May 18, 2009 at 1:14 PM, Andrei Alexandrescu
> <SeeWebsiteForEmail at erdani.org> wrote:
>> Nick Sabalausky wrote:
>>> "Leandro Lucarella" <llucax at gmail.com> wrote in message
>>> news:20090518141908.GB9277 at burns.springfield.home...
>>>> bearophile, el 18 de mayo a las 04:33 me escribiste:
>>>>> Andrei, I agree that "with" is dangerous when it shadows outer names
>>>>> (Python designers have not added a "with" because of this).
>>>> They did, but with different semantics =)
>>>> It's used for RAII (I guess you already know that, but maybe other people
>>>> don't).
>>>>
>>> You mean like C#'s "using"?
>> What a God awful feature. Honestly, "what were they sinking about?" People
>> who explained that C# is cool - please explain this one.
> 
> Looks like
> 
> using(Foo x = new Foo()) {
>      // do stuff
> }
> 
> It's basically equiv of
> 
> {
>     auto x = new Foo();
>     scope(exit) foo.Dispose;
>     // do stuff
> }
> 
> So it saves a little typing but is capable of less.  scope(exit) is way cooler.
> Python has a similar feature to C#'s using.  In Python it's called
> "with".  http://effbot.org/zone/python-with-statement.htm

That's not an "equiv of". It's "completely missing the point of". Each 
"using" costs one new scope and one level of indentation which makes it 
non-scalable. Indentation is *expensive*. I think the C# folks missed 
the class when try/catch/finally showed with extensive examples just how 
expensive extra indentation is.

Andrei