Understanding Rust Error E0586: Inclusive Range with No End

Overview of the Error

Rust Error E0586 occurs when an inclusive range is used without specifying an end value. An inclusive range requires an end value to determine its bounds. This error can be resolved by adding an end value or using a non-inclusive range.

Example of Erroneous Code

fn main() {
    let tmp = vec![0, 1, 2, 3, 4, 4, 3, 3, 2, 1];
    let x = &tmp[1..=]; // error: inclusive range was used with no end
}

In this example, the inclusive range is missing an end value, causing the Rust compiler to throw the E0586 error.

Fixing the Error

To fix the E0586 error, an end value can be added to the inclusive range or a non-inclusive range can be used. Both solutions are demonstrated below.

Using a Non-Inclusive Range

fn main() {
    let tmp = vec![0, 1, 2, 3, 4, 4, 3, 3, 2, 1];
    let x = &tmp[1..]; // ok!
}

This solution replaces the inclusive range with a non-inclusive range, eliminating the need for an end value.

Adding an End Value to the Inclusive Range

fn main() {
    let tmp = vec![0, 1, 2, 3, 4, 4, 3, 3, 2, 1];
    let x = &tmp[1..=3]; // ok!
}

In this example, an end value of 3 is added to the inclusive range, fixing the error and allowing the code to compile and run successfully.