I have a struct like this

Struct
{
void go(T)(T v){}
}

and I want to only allow access to go with a finite set of parameters. My first thought was this:

Struct
{
private void goT(T)(T v){}
public alias goT!(int) go;
public alias goT!(char) go;
public alias goT!(byte) go;
public alias goT!(float) go;
}

But you cant tunnel through private with a public alias. Does anyone known of a clean get somthing like this? Wrapper functions are not an option.

BCS wrote:
> I have a struct like this
> 
> Struct
> {
> void go(T)(T v){}
> }
> 
> and I want to only allow access to go with a finite set of parameters. My first thought was this:
> 
> Struct
> {
> private void goT(T)(T v){}
> public alias goT!(int) go;
> public alias goT!(char) go;
> public alias goT!(byte) go;
> public alias goT!(float) go;
> }
> 
> But you cant tunnel through private with a public alias. Does anyone known of a clean get somthing like this? Wrapper functions are not an option.
> 
> 

I don't know of any way to expose public names for private things in quite that way, but you might consider something like this:

private void goT(T)(T v){
  static if (!(is(T == int) || is(T == char) || is(T == byte) || is(T == float))) {
    static assert (false, "...useful message...");
  }

  // ... code ...
}

Not super pretty, I know, but it should work.  It would be nice if there were a cleaner way of doing this for those cases where the list is long.  (I have something I would've liked to templatize in a similar fashion, but with about 10 types to support.)

-- Chris Nicholson-Sauls

Reply to Chris Nicholson-Sauls,

> I don't know of any way to expose public names for private things in
> quite that way, but you might consider something like this:
> 
> private void goT(T)(T v){
> static if (!(is(T == int) || is(T == char) || is(T == byte) || is(T
> == float))) {
> static assert (false, "...useful message...");
> }
> // ... code ...
> }
> Not super pretty, I know, but it should work.  It would be nice if
> there were a cleaner way of doing this for those cases where the list
> is long.  (I have something I would've liked to templatize in a
> similar fashion, but with about 10 types to support.)
> 

Yeah, I guess I could do that. But I also have a bunch of other stuff that would have to be checked. I guess I could make it all public and then make threats against the lives on anyone who uses the template directly. :b