Should alias expand visibility?

[Tomek Sowiński]

Steven Schveighoffer wrote:

> On Tue, 27 Jul 2010 14:42:12 -0400, Tomek Sowiński <just at ask.me> wrote:
> 
>> Steven Schveighoffer wrote:
>>
>>> I think the better argument is that it serves
>>> no purpose to have a private alias to a public function.  You can just
>>> as
>>> easily call the public function.
>>
>> private alias ClassFromModuleBeyondReach.awkwardStaticName awkwardHelper;
> 
> This is a good point.  But we are talking about aliasing a private
> function into a public one. 

You said "private alias to a public function", look above ;)

> Which means both must be defined in the same
> module.  Which means the symbol being aliased is not beyond reach, and is
> probably pretty easy to call.
> 
> But let's expand on this.  Let's assume I have:
> 
> private void funcA() {}
> public alias funcA funcB;

Now import funcB from another module. It fails. If such an alias is wrong 
(not completely sure) then the compiler should flag it already where it's 
declared.

> How is this different than:
> 
> public void funcB() {}
> private alias funcB funcA;

Because this always works (can use the alias) and the above doesn't.

> It doesn't lend itself well to your example of byColumn and byRows,
> because you want to define the private function.  The problem really comes
> down to the fact that you can't make a static decision for the name of the
> function, because then you have to repeat the whole function.
> 
> But I'm not sure how easy it would be to implement.  I also note from some
> experimentation that aliasing member variables doesn't work?  That should
> probably be fixed.
> 
> The "issue" of having a private function have to be declared public is not
> a huge one though.  I don't see this being convincing enough to Walter,
> but maybe he would consider it.  It's definitely worth putting into
> bugzilla.

Yeah, but what? That visibility expanding aliases should be useable or that 
the compiler should ban such declarations? I'm veering towards banning 
because of alias-presence-may-alter-generated-code issue I mentioned in the 
other post.


Tomek