Range Redesign: Copy Semantics

[Paul Backus]

On Sunday, 21 January 2024 at 18:26:37 UTC, Sebastiaan Koppe 
wrote:
> What about:
>
>     bool next(Callable)(Callable c) {
>         if (empty)
>             return false;
>         c(front());
>         popFront();
>         return true;
>     }
>
> It has the benefit of not needing to unbox a Nullable/Pointer.

If your concern is performance, an indirect function call is 
going to hurt a lot more than a pointer dereference.

If your concern is aesthetics, dereferencing a pointer or 
unboxing a Nullable is far less ugly than passing a callback.

     // With pointer
     while (auto p = r.next)
         doStuffWith(*p);

     // With callback
     while (r.next((e) { doStuffWith(e); })) {}