As someone who uses D and has been doing things like what you see in the post for a long time, I wonder why other languages would put attention to these tricks and steal them when they have been completely ignoring them forever when done in D. Perhaps Zig will make these features more popular, but I'm skeptic.
I was trying to implement this trick in D using basic enum, but couldn't find a solution that works at compile-time, like in Zig. Could you show how to do that?
import std.meta: AliasSeq;
enum E { a, b, c }
void handle(E e)
{
// Need label to break out of 'static foreach'
Lswitch: final switch (e)
{
static foreach (ab; AliasSeq!(E.a, E.b))
{
case ab:
handleAB();
// No comptime switch in D
static if (ab == E.a)
handleA();
else static if (ab == E.b)
handleB();
else
static assert(false, "unreachable");
break Lswitch;
}
case E.c:
handleC();
break;
}
}
Thanks! That indeed does the equivalent as the Zig code... but feels a bit pointless to do that in D, I think?
Could've done this and be as safe, but perhaps it loses the point of the article:
enum U { A, B, C }
void handle(U e)
{
with (U)
final switch (e) {
case A, B:
handleAB();
if (e == A) handleA(); else handleB();
break;
case C:
handleC();
break;
}
}
