rust/tests/ui/dst/issue-90528-unsizing-suggestion-4.rs

// Issue #90528: provide helpful suggestions when a trait bound is unsatisfied
// due to a missed unsizing coercion.
//
// This test exercises array variables and a trait implemented on mutable slices.

trait Write {}

impl Write for &mut [u8] {}

fn wants_write(_: impl Write) {}

fn main() {
    let mut x = [0u8];
    wants_write(x);
    //~^ ERROR the trait bound `[u8; 1]: Write` is not satisfied
    wants_write(&mut x);
    //~^ ERROR the trait bound `&mut [u8; 1]: Write` is not satisfied
    wants_write(&mut x[..]);

    let x = &mut [0u8];
    wants_write(x);
    //~^ ERROR the trait bound `&mut [u8; 1]: Write` is not satisfied
    wants_write(*x);
    //~^ ERROR the trait bound `[u8; 1]: Write` is not satisfied
    wants_write(&mut x[..]);
}