// error-pattern:assigning to immutable class field class cat { priv { let mutable meows : uint; } let how_hungry : int; fn eat() { how_hungry -= 5; } new(in_x : uint, in_y : int) { meows = in_x; how_hungry = in_y; } } fn main() { let nyan : cat = cat(52u, 99); nyan.eat(); }