[Issue 13196] Infer struct/class template args from constructor args

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=13196

Steven Schveighoffer <schveiguy at yahoo.com> changed:

           What    |Removed                     |Added
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                 CC|                            |schveiguy at yahoo.com

--- Comment #3 from Steven Schveighoffer <schveiguy at yahoo.com> ---
(In reply to Jakob Ovrum from comment #1)
> This has been discussed before, and there is even a DIP for it. See #6082.
> 
> It's not so easy to do in the general case:
> 
> ---
> struct S(T)
> {
>     static if(is(T == bool))
>     {
>         this(T[] t) {}
>     }
>     else
>     {
>         this(int i) {}
>     }
> }
> 
> auto s = S([true, false]);
> auto s2 = S(2);
> ---
> 
> How do you propose we deduce T for the above two?

I'll respond here since the question is here.

Answer: you don't. Just like you can't do IFTI on this:

template foo(T)
{
   static if(is(T == bool))
      void foo(T t) {}
   else
      void foo(int t) {}
}

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