1 // check-pass 2 // run-rustfix 3 // edition 2018 4 #![warn(rust_2021_prelude_collisions)] 5 6 trait MyTrait<A> { from_iter(x: Option<A>)7 fn from_iter(x: Option<A>); 8 } 9 10 impl<T> MyTrait<()> for Vec<T> { from_iter(_: Option<()>)11 fn from_iter(_: Option<()>) {} 12 } 13 main()14fn main() { 15 <Vec<i32>>::from_iter(None); 16 //~^ WARNING trait-associated function `from_iter` will become ambiguous in Rust 2021 17 //~^^ WARNING this is accepted in the current edition 18 } 19