Add support implicit conversion between types

[ilya-stromberg]

On Friday, 6 September 2013 at 17:15:03 UTC, H. S. Teoh wrote:
> Hmm, could this be a possible (though somewhat ugly) workaround?
>
> 	foreach (T; IntegralTypeList)
> 	{
> 		assert(factorial(to!T(3) == 6));
> 	}
>
> AFAIK, if T==int, then std.conv.to should simply alias itself 
> away. And
> it *should* be able to handle ctors that take the requisite 
> type, I
> think.

I use:

  	foreach (T; IntegralTypeList)
  	{
  		assert(factorial(cast(T)3) == 6));
  	}

I works, but looks a little strange.
I belive that compiler should optimise this (do nothing), but I 
am not sure.