| // See https://github.com/rust-lang/rust/issues/88442 | 
 | //@ run-rustfix | 
 | //@ edition:2018 | 
 | //@ check-pass | 
 | #![allow(unused)] | 
 | #![warn(rust_2021_prelude_collisions)] | 
 |  | 
 | trait AnnotatableTryInto { | 
 |     fn try_into<T>(self) -> Result<T, Self::Error> | 
 |     where Self: std::convert::TryInto<T> { | 
 |         std::convert::TryInto::try_into(self) | 
 |     } | 
 | } | 
 |  | 
 | impl<T> AnnotatableTryInto for T where T: From<u8> {} | 
 |  | 
 | fn main() -> Result<(), &'static str> { | 
 |     let x: u64 = 1; | 
 |     x.try_into::<usize>().or(Err("foo"))?.checked_sub(1); | 
 |     //~^ WARNING trait method `try_into` will become ambiguous in Rust 2021 | 
 |     //~| WARNING this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! | 
 |  | 
 |     x.try_into::<usize>().or(Err("foo"))?; | 
 |     //~^ WARNING trait method `try_into` will become ambiguous in Rust 2021 | 
 |     //~| WARNING this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021! | 
 |  | 
 |     Ok(()) | 
 | } |