discrimination of constructors with same number of parameters

[Guilherme Vieira]

On Thu, Dec 30, 2010 at 12:18 PM, spir <denis.spir at gmail.com> wrote:

> On Thu, 30 Dec 2010 08:15:51 -0500
> bearophile <bearophileHUGS at lycos.com> wrote:
>
> > > But some language types (or machine types) can have very diverse
> _human_ semantics, and thus be used for various purposes which should, but
> cannot, be considered different:
> >
> > You may wrap your data in a struct.
>
> Yes, thank you for this hint. A kind of proxy struct? It can indeed be used
> everywhere performance is not critical. But a side issue is that it requires
> the 'alias this' hack, I guess, or forwarding every operation to the actual,
> but wrapped, element. What do you think
>
> Denis
> -- -- -- -- -- -- --
> vit esse estrany ☣
>
> spir.wikidot.com
>
>
Why is performance harmed by the use of a struct? Wouldn't it be
zero-overhead like C++'s std::auto_ptr?

Also, the alias this and the forward might be a real good solution. And a
mixin like Luger's might be jackpot, really. I just dislike the use in:

func2(Position(1)); // implicit conversion to int with alias this


I guess that can be actually a bug, not a feature :) Maybe one day the
function signature changes slightly and the problem is further disguised
because "you're obviously passing the right Position here"... when it's
actually an "int count" thing. The "alias this" thing is a good shorthand
when assigning, though:

int a = pos; // implicit conversion from Position to int instead of
int b = pos.base;


-- 
Atenciosamente / Sincerely,
Guilherme ("n2liquid") Vieira
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