visibility modifiers ignored for method-defining macros

[blaenk]

I created a macro that intended to define a public static method in an implementation. However, the pub modifier is essentially ignored. First, it's apparently not allowed within the macro definition, and then it's ignored if I put it outside and before the macro call:

mod m {
    macro_rules! render_function {
        ($name:ident) => (
            fn $name(output: &mut i32, input: &i32) -> i32 {
                5i32
            }
        );
    }

    struct S;

    impl S {
        fn x() {}

        pub render_function!(test);
    }
}

fn main() {
    let x = m::S::test(&mut 3, &4);
}

<anon>:20:13: 20:23 error: static method `test` is private
<anon>:20     let x = m::S::test(&mut 3, &4);

playpen

[blaenk]

For completeness I should state what is probably already obvious, that as a workaround I ended up having to contain an entire impl within the macro definition which itself contained the function definition, like this:

macro_rules! render_function {
    ($name:ident) => (
        impl S {
            pub fn $name(output: &mut i32, input: &i32) -> i32 {
                5i32
            }
        }
    );
}

[blaenk]

If I change this to define a function in a module (instead of in a struct impl), it does allow me to put pub before the fn within the macro definition and it isn't ignored, whereas, as I said in the first post, if I put pub fn in the macro definition and then call the macro inside the struct impl, it would complain about a syntax error.

[shepmaster]

Dupe of #17436 or #18317 or #14660?

[alexcrichton]

I believe so, thanks @shepmaster!