src/test/ui/regions/regions-assoc-type-in-supertrait-outlives-container.rs

// Test that we are imposing the requirement that every associated
// type of a bound that appears in the where clause on a struct must
// outlive the location in which the type appears, even when the
// associted type is in a supertype. Issue #22246.

// revisions: ast mir
//[mir]compile-flags: -Z borrowck=mir

#![allow(dead_code)]

///////////////////////////////////////////////////////////////////////////

pub trait TheTrait {
    type TheAssocType;
}

pub trait TheSubTrait : TheTrait {
}

pub struct TheType<'b> {
    m: [fn(&'b()); 0]
}

impl<'b> TheTrait for TheType<'b> {
    type TheAssocType = &'b ();
}

impl<'b> TheSubTrait for TheType<'b> {
}

///////////////////////////////////////////////////////////////////////////

pub struct WithAssoc<T:TheSubTrait> {
    m: [T; 0]
}

fn with_assoc<'a,'b>() {
    // For this type to be valid, the rules require that all
    // associated types of traits that appear in `WithAssoc` must
    // outlive 'a. In this case, that means TheType<'b>::TheAssocType,
    // which is &'b (), must outlive 'a.

    // FIXME (#54943) NLL doesn't enforce WF condition in unreachable code if
    // `_x` is changed to `_`
    let _x: &'a WithAssoc<TheType<'b>> = loop { };
    //[ast]~^ ERROR reference has a longer lifetime
    //[mir]~^^ ERROR lifetime may not live long enough
}

fn main() {
}