E0276.md

A trait implementation has stricter requirements than the trait definition.

Erroneous code example:

trait Foo {
    fn foo<T>(x: T);
}

impl Foo for bool {
    fn foo<T>(x: T) where T: Copy {}
}

Here, all types implementing Foo must have a method foo<T>(x: T) which can take any type T. However, in the impl for bool, we have added an extra bound that T is Copy, which isn't compatible with the original trait.

Consider removing the bound from the method or adding the bound to the original method definition in the trait.