pub struct A;
pub struct B;

pub trait Foo {
    type T: PartialEq<A> + PartialEq<B>;
}

pub fn generic<F: Foo>(t: F::T, a: A, b: B) -> bool {
    t == a && t == b
}

error: mismatched types [--explain E0308]
  --> a.rs:12:10
   |>
12 |>     t == a && t == b
   |>          ^ expected struct `B`, found struct `A`
note: expected type `B`
note:    found type `A`

error: aborting due to previous error

    PartialEq::<A>::eq(&t, &a) && t == b