// `Self` nested inside a SLICE in a protocol-method param resolves
// correctly: the conformance gate substitutes `Self → T` THROUGH the
// `[]` wrapper (and the `*Self` receiver), so a correct `[]T` impl is
// accepted and dispatched — not falsely rejected as `[]Self` ≠ `[]T`.
//
// Regression (issue 0178 adversarial review): the signature gate's
// `Self`-substitution originally only reached the bare leaf and a
// one-level pointer/optional wrapper, so `[]Self` resolved to a real
// slice named `[]Self` and a correct `[]T` impl was WRONGLY flagged.
#import "modules/std.sx";

P :: protocol {
    // `*Self` receiver + `[]Self` slice param + `Self` value param.
    total :: (self: *Self, xs: []Self, extra: Self) -> i64;
}

T :: struct { n: i64 = 0; }

impl P for T {
    total :: (self: *T, xs: []T, extra: T) -> i64 {
        sum := self.n + extra.n;
        for xs (x) { sum = sum + x.n; }
        return sum;
    }
}

main :: () {
    t := T.{ n = 10 };
    p : P = t;
    arr : [3]T = .{ T.{ n = 1 }, T.{ n = 2 }, T.{ n = 3 } };
    // 10 (self) + 1+2+3 (slice) + 100 (extra) = 116
    print("{}\n", p.total(arr[..], T.{ n = 100 }));
}