[rustc.git] / src / test / ui / variance / variance-trait-object-bound.rs

// Checks that regions which appear in a trait object type are
// observed by the variance inference algorithm (and hence
// `TOption` is contavariant w/r/t `'a` and not bivariant).
//
// Issue #18262.

#![feature(rustc_attrs)]

use std::mem;

trait T { fn foo(&self); }

#[rustc_variance]
struct TOption<'a> { //~ ERROR [-]
    v: Option<Box<dyn T + 'a>>,
}

fn main() { }
Commit	Line	Data
1a4d82fc JJ	1	// Checks that regions which appear in a trait object type are
	2	// observed by the variance inference algorithm (and hence
	3	// `TOption` is contavariant w/r/t `'a` and not bivariant).
	4	//
	5	// Issue #18262.
223e47cc	6
85aaf69f SL	7	#![feature(rustc_attrs)]
85aaf69f SL	8
1a4d82fc	9	use std::mem;
970d7e83	10
85aaf69f	11	trait T { fn foo(&self); }
223e47cc	12
1a4d82fc	13	#[rustc_variance]
9e0c209e	14	struct TOption<'a> { //~ ERROR [-]
dc9dc135	15	v: Option<Box<dyn T + 'a>>,
223e47cc	16	}
1a4d82fc JJ	17
1a4d82fc JJ	18	fn main() { }