// Generic inference where `$R` comes from a worker closure's RETURN type
// through a variadic `..$args` pack — both the DIRECT spelling
// `mymk(bx, worker, 40, 2)` and the UFCS dot-call `bx.mymk(worker, 40, 2)`
// resolve `$R = i64` identically and build `Wrap($R)` correctly.
// Regression (issue 0151): the UFCS path used to splice the receiver as
// arg 0 without running the direct path's pack/closure-return binding, so
// `$R` stayed `.unresolved` and SIGTRAPped at LLVM emission.
#import "modules/std.sx";

Box  :: struct { n: i64; }
Wrap :: struct ($R: Type) { value: R; }

mymk :: ufcs (b: Box, worker: Closure(..$args) -> $R, ..$args) -> Wrap($R) {
    f : Wrap($R) = ---;
    f.value = worker(..args);
    return f;
}

main :: () -> i32 {
    bx : Box = .{ n = 1 };
    direct := mymk(bx, (a: i64, b: i64) -> i64 => a + b, 40, 2);
    ufcs   := bx.mymk((a: i64, b: i64) -> i64 => a + b, 40, 2);
    print("direct={}\n", direct.value);
    print("ufcs={}\n", ufcs.value);
    return 0;
}