// Feature 1 — method calls on a PARAMETERIZED protocol pack (the canonical
// shape: `..xs: ValueListenable` where each element conforms with its own
// type-arg). Calling the protocol method `get()` on `xs[i]` resolves to the
// concrete element's impl, even though each element binds a different `T`.
//
// (Parameterised-protocol impl methods with a concrete source type are now
// registered as `<Source>.<method>`, so UFCS — and thus `xs[i].get()` —
// resolves them.)

#import "modules/std.sx";

Box :: protocol(T: Type) {
    get :: () -> T;
}

IntCell :: struct { v: s64; }
StrCell :: struct { s: string; }
impl Box(s64) for IntCell { get :: (self: *IntCell) -> s64 => self.v; }
impl Box(string) for StrCell { get :: (self: *StrCell) -> string => self.s; }

describe :: (..xs: Box) -> void {
    // xs[0] : Box(s64), xs[1] : Box(string) — different type-args per position.
    print("first={} second={}\n", xs[0].get(), xs[1].get());
}

main :: () -> s32 {
    describe(IntCell.{ v = 11 }, StrCell.{ s = "hi" });
    describe(StrCell.{ s = "x" }, IntCell.{ v = 99 });
    0
}