src/test/ui/type/type-ascription-soundness.rs

// Type ascription doesn't lead to unsoundness

#![feature(type_ascription)]

fn main() {
    let arr = &[1u8, 2, 3];
    let ref x = arr: &[u8]; //~ ERROR mismatched types
    let ref mut x = arr: &[u8]; //~ ERROR mismatched types
    match arr: &[u8] { //~ ERROR mismatched types
        ref x => {}
    }
    let _len = (arr: &[u8]).len(); //~ ERROR mismatched types
}