rust/src/test/run-pass/uniform-paths/macros-nested.rs

// run-pass
#![allow(non_camel_case_types)]

// edition:2018

#![feature(uniform_paths)]

// This test is similar to `macros.rs`, but nested in modules.

mod foo {
    // Test that ambiguity errors are not emitted between `self::test` and
    // `::test`, assuming the latter (crate) is not in `extern_prelude`.
    macro_rules! m1 {
        () => {
            mod test {
                pub struct Foo(pub ());
            }
        }
    }
    pub use test::Foo;
    m1!();

    // Test that qualified paths can refer to both the external crate and local item.
    macro_rules! m2 {
        () => {
            mod std {
                pub struct io(pub ());
            }
        }
    }
    pub use ::std::io as std_io;
    pub use self::std::io as local_io;
    m2!();
}

// Test that we can refer to the external crate unqualified
// (when there isn't a local item with the same name).
use std::io;

mod bar {
    // Also test the unqualified external crate import in a nested module,
    // to show that the above import doesn't resolve through a local `std`
    // item, e.g., the automatically injected `extern crate std;`, which in
    // the Rust 2018 should no longer be visible through `crate::std`.
    pub use std::io;
}


fn main() {
    foo::Foo(());
    foo::std_io::stdout();
    foo::local_io(());
    io::stdout();
    bar::io::stdout();
}