Template pattern delegate?

[Jacob Carlborg]

On Monday, 26 October 2020 at 00:56:26 UTC, frame wrote:

> I see that your approach can handle functions and delegates but 
> isn't that not equivalent like this template for a function?
>
> auto myStuff(T)(T function() fn) {
>     try {
>         return fn();
>     }
>     catch (Exception e) {
>         //
>     }
> }

You cannot pass a delegate to something that expects a function 
pointer.

> I wonder if I could use such a template as static variant and 
> the compiler just expands the code? Just thinking that using a 
> function or delegate is an overhead. Maybe not a function but a 
> delegate will allocate GC memory I think.

If you pass the delegate as a template parameter/alias parameter, 
it's more likely to be inlined:

auto myStuff(alias fn)() {
     try return fn();
     catch (Exception e) { }
}

myStuff!( { /* some code */ } );

--
/Jacob Carlborg