rust/tests/ui/range_plus_minus_one.fixed

#![warn(clippy::range_minus_one, clippy::range_plus_one)]
#![allow(unused_parens)]
#![allow(clippy::iter_with_drain)]

use std::ops::{Index, IndexMut, Range, RangeBounds, RangeInclusive};

fn f() -> usize {
    42
}

macro_rules! macro_plus_one {
    ($m: literal) => {
        for i in 0..$m + 1 {
            println!("{}", i);
        }
    };
}

macro_rules! macro_minus_one {
    ($m: literal) => {
        for i in 0..=$m - 1 {
            println!("{}", i);
        }
    };
}

fn main() {
    for _ in 0..2 {}
    for _ in 0..=2 {}

    for _ in 0..=3 {}
    //~^ range_plus_one
    for _ in 0..=3 + 1 {}

    for _ in 0..=5 {}
    //~^ range_plus_one
    for _ in 0..=1 + 5 {}

    for _ in 1..=1 {}
    //~^ range_plus_one
    for _ in 1..=1 + 1 {}

    for _ in 0..13 + 13 {}
    for _ in 0..=13 - 7 {}

    for _ in 0..=f() {}
    //~^ range_plus_one
    for _ in 0..=(1 + f()) {}

    // Those are not linted, as in the general case we cannot be sure that the exact type won't be
    // important.
    let _ = ..11 - 1;
    let _ = ..=11 - 1;
    let _ = ..=(11 - 1);
    let _ = (1..11 + 1);
    let _ = (f() + 1)..(f() + 1);

    const ONE: usize = 1;
    // integer consts are linted, too
    for _ in 1..=ONE {}
    //~^ range_plus_one

    let mut vec: Vec<()> = std::vec::Vec::new();
    vec.drain(..);

    macro_plus_one!(5);
    macro_minus_one!(5);

    // As an instance of `Iterator`
    (1..=10).for_each(|_| {});
    //~^ range_plus_one

    // As an instance of `IntoIterator`
    #[allow(clippy::useless_conversion)]
    (1..=10).into_iter().for_each(|_| {});
    //~^ range_plus_one

    // As an instance of `RangeBounds`
    {
        let _ = (1..=10).start_bound();
        //~^ range_plus_one
    }

    // As a `SliceIndex`
    let a = [10, 20, 30];
    let _ = &a[1..=1];
    //~^ range_plus_one

    // As method call argument
    vec.drain(2..=3);
    //~^ range_plus_one

    // As function call argument
    take_arg(10..=20);
    //~^ range_plus_one

    // As function call argument inside a block
    take_arg({ 10..=20 });
    //~^ range_plus_one

    // Do not lint in case types are unified
    take_arg(if true { 10..20 } else { 10..20 + 1 });

    // Do not lint, as the same type is used for both parameters
    take_args(10..20 + 1, 10..21);

    // Do not lint, as the range type is also used indirectly in second parameter
    take_arg_and_struct(10..20 + 1, S { t: 1..2 });

    // As target of `IndexMut`
    let mut a = [10, 20, 30];
    a[0..=2][0] = 1;
    //~^ range_plus_one
}

fn take_arg<T: Iterator<Item = u32>>(_: T) {}
fn take_args<T: Iterator<Item = u32>>(_: T, _: T) {}

struct S<T> {
    t: T,
}
fn take_arg_and_struct<T: Iterator<Item = u32>>(_: T, _: S<T>) {}

fn no_index_by_range_inclusive(a: usize) {
    struct S;

    impl Index<Range<usize>> for S {
        type Output = [u32];
        fn index(&self, _: Range<usize>) -> &Self::Output {
            &[]
        }
    }

    _ = &S[0..a + 1];
}

fn no_index_mut_with_switched_range(a: usize) {
    struct S(u32);

    impl Index<Range<usize>> for S {
        type Output = u32;
        fn index(&self, _: Range<usize>) -> &Self::Output {
            &self.0
        }
    }

    impl IndexMut<Range<usize>> for S {
        fn index_mut(&mut self, _: Range<usize>) -> &mut Self::Output {
            &mut self.0
        }
    }

    impl Index<RangeInclusive<usize>> for S {
        type Output = u32;
        fn index(&self, _: RangeInclusive<usize>) -> &Self::Output {
            &self.0
        }
    }

    S(2)[0..a + 1] = 3;
}

fn issue9908() {
    // Simplified test case
    let _ = || 0..=1;

    // Original test case
    let full_length = 1024;
    let range = {
        // do some stuff, omit here
        None
    };

    let range = range.map(|(s, t)| s..=t).unwrap_or(0..=(full_length - 1));

    assert_eq!(range, 0..=1023);
}

fn issue9908_2(n: usize) -> usize {
    (1..n).sum()
    //~^ range_minus_one
}