rust-clippy/tests/ui/explicit_counter_loop.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::explicit_counter_loop)]

fn main() {
    let mut vec = vec![1, 2, 3, 4];
    let mut _index = 0;
    for _v in &vec {
        _index += 1
    }

    let mut _index = 1;
    _index = 0;
    for _v in &vec {
        _index += 1
    }
}

mod issue_1219 {
    pub fn test() {
        // should not trigger the lint because variable is used after the loop #473
        let vec = vec![1, 2, 3];
        let mut index = 0;
        for _v in &vec {
            index += 1
        }
        println!("index: {}", index);

        // should not trigger the lint because the count is conditional #1219
        let text = "banana";
        let mut count = 0;
        for ch in text.chars() {
            if ch == 'a' {
                continue;
            }
            count += 1;
            println!("{}", count);
        }

        // should not trigger the lint because the count is conditional
        let text = "banana";
        let mut count = 0;
        for ch in text.chars() {
            if ch == 'a' {
                count += 1;
            }
            println!("{}", count);
        }

        // should trigger the lint because the count is not conditional
        let text = "banana";
        let mut count = 0;
        for ch in text.chars() {
            count += 1;
            if ch == 'a' {
                continue;
            }
            println!("{}", count);
        }

        // should trigger the lint because the count is not conditional
        let text = "banana";
        let mut count = 0;
        for ch in text.chars() {
            count += 1;
            for i in 0..2 {
                let _ = 123;
            }
            println!("{}", count);
        }

        // should not trigger the lint because the count is incremented multiple times
        let text = "banana";
        let mut count = 0;
        for ch in text.chars() {
            count += 1;
            for i in 0..2 {
                count += 1;
            }
            println!("{}", count);
        }
    }
}

mod issue_3308 {
    pub fn test() {
        // should not trigger the lint because the count is incremented multiple times
        let mut skips = 0;
        let erasures = vec![];
        for i in 0..10 {
            while erasures.contains(&(i + skips)) {
                skips += 1;
            }
            println!("{}", skips);
        }

        // should not trigger the lint because the count is incremented multiple times
        let mut skips = 0;
        for i in 0..10 {
            let mut j = 0;
            while j < 5 {
                skips += 1;
                j += 1;
            }
            println!("{}", skips);
        }

        // should not trigger the lint because the count is incremented multiple times
        let mut skips = 0;
        for i in 0..10 {
            for j in 0..5 {
                skips += 1;
            }
            println!("{}", skips);
        }
    }
}