rust/tests/ui/shadow.rs

// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// 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.

#![warn(
    clippy::all,
    clippy::pedantic,
    clippy::shadow_same,
    clippy::shadow_reuse,
    clippy::shadow_unrelated
)]
#![allow(unused_parens, unused_variables, clippy::missing_docs_in_private_items)]

fn id<T>(x: T) -> T {
    x
}

fn first(x: (isize, isize)) -> isize {
    x.0
}

fn main() {
    let mut x = 1;
    let x = &mut x;
    let x = { x };
    let x = (&*x);
    let x = { *x + 1 };
    let x = id(x);
    let x = (1, x);
    let x = first(x);
    let y = 1;
    let x = y;

    let x;
    x = 42;

    let o = Some(1_u8);

    if let Some(p) = o {
        assert_eq!(1, p);
    }
    match o {
        Some(p) => p, // no error, because the p above is in its own scope
        None => 0,
    };

    match (x, o) {
        (1, Some(a)) | (a, Some(1)) => (), // no error though `a` appears twice
        _ => (),
    }
}