rust/tests/ui/impl-header-lifetime-elision/dyn-trait.rs
2023-01-11 09:32:08 +00:00

37 lines
856 B
Rust

// Test that `impl MyTrait<'_> for &i32` is equivalent to `impl<'a,
// 'b> MyTrait<'a> for &'b i32`.
#![allow(warnings)]
use std::fmt::Debug;
// Equivalent to `Box<dyn Debug + 'static>`:
trait StaticTrait { }
impl StaticTrait for Box<dyn Debug> { }
// Equivalent to `Box<dyn Debug + 'static>`:
trait NotStaticTrait { }
impl NotStaticTrait for Box<dyn Debug + '_> { }
// Check that we don't err when the trait has a lifetime parameter.
trait TraitWithLifetime<'a> { }
impl NotStaticTrait for &dyn TraitWithLifetime<'_> { }
fn static_val<T: StaticTrait>(_: T) {
}
fn with_dyn_debug_static<'a>(x: Box<dyn Debug + 'a>) {
static_val(x);
//~^ ERROR borrowed data escapes outside of function
}
fn not_static_val<T: NotStaticTrait>(_: T) {
}
fn with_dyn_debug_not_static<'a>(x: Box<dyn Debug + 'a>) {
not_static_val(x); // OK
}
fn main() {
}