issue-90528-unsizing-suggestion-3.rs

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

trait Write {}

impl Write for & mut [u8] {}

fn wants_write(_: impl Write) {}

fn main() {
    wants_write([0u8]);
    //~^ ERROR the trait bound `[u8; 1]: Write` is not satisfied
    //~| HELP the following implementations were found
    //~| HELP convert the array
    //~| SUGGESTION &mut [0u8][..]
    wants_write(&mut [0u8]);
    //~^ ERROR the trait bound `&mut [u8; 1]: Write` is not satisfied
    //~| HELP the following implementations were found
    //~| HELP convert the array
    //~| SUGGESTION &mut [0u8][..]
    wants_write(&mut [0u8][..]);

    wants_write(&[0u8]);
    //~^ ERROR the trait bound `&[u8; 1]: Write` is not satisfied
    //~| HELP the following implementations were found

    wants_write(&[0u8][..]);
    //~^ ERROR the trait bound `&[u8]: Write` is not satisfied
    //~| HELP the following implementations were found
    //~| HELP consider changing this borrow's mutability
}