v/vlib/v/checker/tests/immutable_interface_field.vv

struct Aaa {
	i1 int
}

interface Bbb {
	i1 int
}

fn mutate_interface(mut b Bbb) {
	b.i1 = 2
}

fn main() {
	mut a := Aaa{1}
	mutate_interface(mut a)
}