On Thu, 12 Mar 2009 23:20:07 +0300, Steven Schveighoffer <schvei...@yahoo.com>
wrote:
On Thu, 12 Mar 2009 16:11:49 -0400, Jarrett Billingsley wrote:
On Thu, Mar 12, 2009 at 9:33 AM, Andrei Alexandrescu
<seewebsiteforem...@erdani.org> wrote:
Hello,
I'm looking for a catchy phrase denoting this D idiom:
template Blah(Stuff)
{
alias ... Blah;
}
i.e., defining inside a template a symbol of the same name as the
template
itself. Then you can use Blah!(X, Y) to mean Blah!(X, Y).Blah.
What would be a catchy, descriptive, and memorable phrase for this?
...Unnecessary?
You know i have to be contrary :P but I have never found a use for
multiple declarations inside a template _except_ when it's used as a
mixin. Most of the time, I declare exactly one symbol inside the
template, and it's always the same name as the template. Having to
specify the name of the template over and over inside it is a blatant
violation of DRY, easy to mess up (typos, changing the template name
etc.) and is hard to diagnose when you do it wrong, since the compiler
just has no idea what you're trying to do and you end up with all
sorts of confusing errors about voids having no value.
How do you do this without the Template Identity syntax?
(I'm going to start calling it this to promote the term I thought was
best ;)
tempalte Blah(T)
{
static if(is(T : int))
alias T Blah;
else
alias T* Blah;
}
-Steve
A new 'tempalte' keyword?
Back on topic, I don't see anything wrong with this code. It defines exactly
one alias.
I also think that it should define exactly one /public/ alias:
template Blah(T)
{
private alias Foo!(T).A Tmp1;
private alias Bar!(Tmp1!(T)).B Tmp2;
static if (Tmp2.C!(T)) {
private alias Tmp2.ResultA Tmp3;
} else {
private alias Tmp2.ResultB Tmp3;
}
/*public*/ alias Tmp3!(Tmp2!(Tmp1!())).C Blah;
}
This syntax makes little sense for template mixins, and that's one more reason
why I proposed separating them (see my other post nearby).
