Labels

Both continue and break can optionally take a label argument that is used to break out of nested loops:

// Copyright 2024 Google LLC
// SPDX-License-Identifier: Apache-2.0

fn main() {
    let s = [[5, 6, 7], [8, 9, 10], [21, 15, 32]];
    let mut elements_searched = 0;
    let target_value = 10;
    'outer: for i in 0..=2 {
        for j in 0..=2 {
            elements_searched += 1;
            if s[i][j] == target_value {
                break 'outer;
            }
        }
    }
    dbg!(elements_searched);
}
  • Labeled break also works on arbitrary blocks, e.g. 
    #![allow(unused)]
fn main() {
// Copyright 2024 Google LLC
// SPDX-License-Identifier: Apache-2.0

'label: {
    break 'label;
    println!("This line gets skipped");
}
}