src/test/run-pass/macro-doc-comments.rs

// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

macro_rules! doc {
    (
        $(#[$outer:meta])*
        mod $i:ident {
            $(#![$inner:meta])*
        }
    ) =>
    (
        $(#[$outer])*
        pub mod $i {
            $(#![$inner])*
        }
    )
}

doc! {
    /// Outer doc
    mod Foo {
        //! Inner doc
    }
}

fn main() { }