const Thing = struct {
    detached: bool = false,

    fn deinit(self: *Thing) void {
        if (!self.detached) {
            doTheCleanup();
        }
    }

    fn consume(self: *Thing) void {
        self.detached = true;
    }
};

test "usage code" {
    var thing = functionThatReturnsAThing();
    defer thing.deinit();

    // ...

    thing.consume();

}