Struct template

[John Colvin via Digitalmars-d-learn]

On Monday, 3 November 2014 at 17:03:33 UTC, deed wrote:
> struct Internal { int i; double d; string s; }
>
> struct External_int {
>   Internal internal;
>   @property Internal* ptr () { return &internal; }
> 	
>   this (int a)
>   {
>     internal.s = "int";
>     internal.i = a;
>   }
> }
>
> struct External (T) {
>   Internal internal;
>   @property Internal* ptr () { return &internal; }
> 	
>   static if (is(typeof(T) == int))
>   {
>     this (T a)
>     {
>       internal.s = "int";
>       internal.i = a;
>     }
>   }
> }
>
> void main ()
> {
>   auto e1 = External_int(1); // Ok
>   auto e2 = External!int(1); // Nope, cannot implicitly
>                              // convert expression (1)
>                              // of type int to Internal
> }
>
>
> Why? And how is this fixed? Thanks.

static if (is(typeof(T) == int))

should be

static if (is(T == int))


T is already a type.