rust/tests/ui/codegen/subtyping-impacts-selection...

45 lines
1.1 KiB
Rust

//@ run-pass
//@ revisions: mir codegen
//@[mir] compile-flags: -Zmir-opt-level=3
//@[codegen] compile-flags: -Zmir-opt-level=0
// A regression test for #107205
#![allow(coherence_leak_check)]
struct Foo<T: 'static>(T);
fn useful<'a>(_: &'a u8) {}
trait GetInner {
type Assoc;
fn muahaha(&mut self) -> Self::Assoc;
}
impl GetInner for Foo<fn(&'static u8)> {
type Assoc = String;
fn muahaha(&mut self) -> String {
String::from("I am a string")
}
}
impl GetInner for Foo<for<'a> fn(&'a u8)> {
type Assoc = [usize; 3];
fn muahaha(&mut self) -> [usize; 3] {
[100; 3]
}
}
fn break_me(hr_fnptr: Box<Foo::<for<'a> fn(&'a u8)>>) -> Box<dyn GetInner<Assoc = String>> {
let lr_fnptr = hr_fnptr as Box<Foo<fn(&'static u8)>>;
lr_fnptr as Box<dyn GetInner<Assoc = String>>
}
fn main() {
drop(Box::new(Foo(useful as fn(&'static u8))) as Box<dyn GetInner<Assoc = String>>);
drop(Box::new(Foo(useful as fn(&u8))) as Box<dyn GetInner<Assoc = [usize; 3]>>);
let mut any = break_me(Box::new(Foo(useful)));
let evil_string = any.muahaha();
assert_eq!(evil_string, "I am a string");
}