rust/src/test/ui/run-pass/imports/imports.rs

// Copyright 2016 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.

#![allow(unused)]

// Like other items, private imports can be imported and used non-lexically in paths.
mod a {
    use a as foo;
    use self::foo::foo as bar;

    mod b {
        use super::bar;
    }
}

mod foo { pub fn f() {} }
mod bar { pub fn f() {} }

pub fn f() -> bool { true }

// Items and explicit imports shadow globs.
fn g() {
    use foo::*;
    use bar::*;
    fn f() -> bool { true }
    let _: bool = f();
}

fn h() {
    use foo::*;
    use bar::*;
    use f;
    let _: bool = f();
}

// Here, there appears to be shadowing but isn't because of namespaces.
mod b {
    use foo::*; // This imports `f` in the value namespace.
    use super::b as f; // This imports `f` only in the type namespace,
    fn test() { self::f(); } // so the glob isn't shadowed.
}

// Here, there is shadowing in one namespace, but not the other.
mod c {
    mod test {
        pub fn f() {}
        pub mod f {}
    }
    use self::test::*; // This glob-imports `f` in both namespaces.
    mod f { pub fn f() {} } // This shadows the glob only in the value namespace.

    fn test() {
        self::f(); // Check that the glob-imported value isn't shadowed.
        self::f::f(); // Check that the glob-imported module is shadowed.
    }
}

// Unused names can be ambiguous.
mod d {
    pub use foo::*; // This imports `f` in the value namespace.
    pub use bar::*; // This also imports `f` in the value namespace.
}

mod e {
    pub use d::*; // n.b. Since `e::f` is not used, this is not considered to be a use of `d::f`.
}

fn main() {}