On 03/25/2013 12:40 PM, Steven Schveighoffer wrote:
> On Mon, 25 Mar 2013 11:31:17 -0400, Ali Çehreli <[email protected]>
wrote:
>
>> This design allows templated constructors:
>>
>> struct S // <-- not a template
>> {
>> this(T)(T t) // <-- template
>> {
>> // ...
>> }
>>
>> // ...
>> }
>>
>> The same in C++...
>
> Templated constructors would not be disallowed if you allowed IFTI on
> templated structs/classes without templated constructors.
It would complicate matters: The parameter would be for the constructor
if the constructor were a template, for the struct otherwise.
> When you decompose constructors, they are simply fucntions, and IFTI
> exists on functions. The same should be allowed for constructors.
I completely agree and that's my point. :) The template parameter list
of the constructor should stay with the constructor.
> There is almost no difference between this:
>
> template foo(T){
> void foo(T t) {}
> }
>
> and this:
>
> struct foo(T){
> this(T t) {}
> }
Actually, the latter is a shorthand for this:
template S(T)
{
struct S
{
T t;
this(U)(U)
{}
}
}
As you see, T comes from the outer template and U stays with the
constructor. It allows the following use:
void main()
{
auto s = S!int(byte.init);
}
>
> -Steve
Ali
