rust/tests/ui/variance/variance-trait-object-bound.rs

19 lines
378 B
Rust

// 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 ['a: +]
v: Option<Box<dyn T + 'a>>,
}
fn main() { }