Method selection with by-val self may choose the wrong implementor

[alexcrichton]

trait Foo {
    fn foo(self) { println!("default") }
}

impl Foo for Box<Foo> {
    fn foo(self) { println!("overridden") }
}

impl Foo for int {
    fn foo(self) { println!("int") }
}

fn main() {
    let f = box 1i as Box<Foo>;
    f.foo();
}

I am under the impression that this test should print overridden, not int.

Nominating.

[alexcrichton]

This was altered recently as part of #15242 (by accident I presume)

[pcwalton]

This is the correct behavior with the system we have today. Object methods such as the second method are considered inherent methods, while methods arising from implementations of a trait such as the first method are considered extension methods. Inherent methods are checked before extension methods and override them.

Perhaps we want to change this behavior, but this is, as stated, not a bug.

[alexcrichton]

Sounds like this is working as intended, surprising!

[alexcrichton]

We can revisit this if it becomes more of a problem.