Error code E0053
The parameters of any trait method must match between a trait implementation and the trait definition.
Erroneous code example:
#![allow(unused)] fn main() { trait Foo { fn foo(x: u16); fn bar(&self); } struct Bar; impl Foo for Bar { // error, expected u16, found i16 fn foo(x: i16) { } // error, types differ in mutability fn bar(&mut self) { } } }