rust-clippy/tests/ui/indexing_slicing.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.




#![feature(plugin)]
#![warn(clippy::indexing_slicing)]
#![warn(clippy::out_of_bounds_indexing)]
#![allow(clippy::no_effect, clippy::unnecessary_operation)]

fn main() {
    let x = [1, 2, 3, 4];
    let index: usize = 1;
    let index_from: usize = 2;
    let index_to: usize = 3;
    x[index];
    &x[index..];
    &x[..index];
    &x[index_from..index_to];
    &x[index_from..][..index_to]; // Two lint reports, one for [index_from..] and another for [..index_to].
    x[4]; // Ok, let rustc's `const_err` lint handle `usize` indexing on arrays.
    x[1 << 3]; // Ok, let rustc's `const_err` lint handle `usize` indexing on arrays.
    &x[..=4];
    &x[1..5];
    &x[5..][..10]; // Two lint reports, one for [5..] and another for [..10].
    &x[5..];
    &x[..5];
    &x[5..].iter().map(|x| 2 * x).collect::<Vec<i32>>();
    &x[0..=4];
    &x[0..][..3];
    &x[1..][..5];

    &x[4..]; // Ok, should not produce stderr.
    &x[..4]; // Ok, should not produce stderr.
    &x[..]; // Ok, should not produce stderr.
    &x[1..]; // Ok, should not produce stderr.
    &x[2..].iter().map(|x| 2 * x).collect::<Vec<i32>>(); // Ok, should not produce stderr.
    &x[0..].get(..3); // Ok, should not produce stderr.
    x[0]; // Ok, should not produce stderr.
    x[3]; // Ok, should not produce stderr.
    &x[0..3]; // Ok, should not produce stderr.

    let y = &x;
    y[0];
    &y[1..2];
    &y[0..=4];
    &y[..=4];

    &y[..]; // Ok, should not produce stderr.

    let empty: [i8; 0] = [];
    empty[0]; // Ok, let rustc's `const_err` lint handle `usize` indexing on arrays.
    &empty[1..5];
    &empty[0..=4];
    &empty[..=4];
    &empty[1..];
    &empty[..4];
    &empty[0..=0];
    &empty[..=0];

    &empty[0..]; // Ok, should not produce stderr.
    &empty[0..0]; // Ok, should not produce stderr.
    &empty[..0]; // Ok, should not produce stderr.
    &empty[..]; // Ok, should not produce stderr.

    let v = vec![0; 5];
    v[0];
    v[10];
    v[1 << 3];
    &v[10..100];
    &x[10..][..100]; // Two lint reports, one for [10..] and another for [..100].
    &v[10..];
    &v[..100];

    &v[..]; // Ok, should not produce stderr.

    //
    // Continue tests at end function to minimize the changes to this file's corresponding stderr.
    //

    const N: usize = 15; // Out of bounds
    const M: usize = 3; // In bounds
    x[N]; // Ok, let rustc's `const_err` lint handle `usize` indexing on arrays.
    x[M]; // Ok, should not produce stderr.
    v[N];
    v[M];

    // issue 3102
    let num = 1;
    &x[num..10]; // should trigger out of bounds error
    &x[10..num]; // should trigger out of bounds error
}