Philippe Sigaud wrote:
> On Fri, Aug 6, 2010 at 21:59, Rory Mcguire <rjmcgu...@gm_no_ail.com>
> wrote:
>
>>
>> Here is a possible solution to your problem:
>>
>> -Rory
>
>
> I believe you can get the type of A. Isn't it typeof(super) or
> std.traits.BaseClassesTuple!B[0] ? B in the latter case being typeof(this)
> That way, there is no need for the user to provide A, it's automatically
> found by the template.
> Warning: I did not test this.
>
> And, we know the constructs are of type 'A function(someTypes)' [*], so
> the 'A function' part is redundant.
> Hence, the user only needs to provide for the args types and that makes
> for a cleaner call.
>
> * either as a list :
> mixin(InheritConstructors!(int, double, string)); // I want to inherit
> the constructors taking one type, build me the __ctors for int, double and
> string
>
> * or, in the case of multi-parameters constructors, wrap them in a tuple:
> mixin(InheritConstructors!(int, double, Tuple!(int, double)); // I
> want
> super(int), super(double) and super(int, double)
>
> That means iterating on the type list, and determining if the current type
> is a tuple or not
> * if its a 'normal' type, create the corresponding contructor
> * if it's a Tuple, crack it open and get the types, using the .Types alias
> std.typecons.Tuples have. Creating a constructor from this typetuple is no
> different from creating it for one type.
>
> To determine if something is a std.typecons.Tuple, you cannot use an is()
> expression: they do not allow multiple types:
>
> enum bool isTuple = is(T == Tuple!U, U...); // no. U... is not allowed.
> Hmm, enhancement request?
>
> So, you can either rely on it having a .Types 'member':
>
> template isTuple(T)
> {
> enum bool isTuple = is(T.Types);
> }
>
> Pb: that will flag as tuples any type that exposes a ".Types" alias.
>
> Or use a function accepting a Tuple:
>
> template isTuple(T)
> {
> enum bool isTuple = is(typeof({
> void foo(U...)(Tuple!U t) {}; // this
> function accepts only tuples
> foo(T.init); // test it
> }()));
> }
>
> It's ugly as a rat's ass, but it's more solid than the former template.
>
>
> Philippe
>
> [*] btw, shouldn't that be A delegate(someTypes)???
I'll see what I can do to shorten it but I'm not sure how to iterate over
the Selectors inside the foreach and still be able to skip unselected
constructors. Hmmm I suppose I could use a temporary boolean or something.
I don't use "A delegate(someTuypes)" because the compiler says that the type
of the constructors is for instance: "A function(int x)"
