`derive(Debug)` fails for generic struct which contains BiMap

[atomicky]

In contrast to normal (non-generic) structs, generic structs which contain BiMap fail deriving and lead to compile error: "`std::cmp::Eq` is not implemented for `K`" etc. (I'm using bimap 0.5.2)

use bimap::BiMap;

#[derive(Debug)] // ok
struct NonGenericStruct {
    map1: BiMap<usize, i32>,
    map2: BiMap<usize, i32>,
}

#[derive(Debug)] // ERROR: e.g. "`std::cmp::Eq` is not implemented for `K`"
struct GenericStruct<K, V> {
    map1: BiMap<K, V>,
    map2: BiMap<K, V>,
}

fn main() {
    let mut map1 = BiMap::new();
    map1.insert(1usize, -1i32);
    map1.insert(2, -2);

    let mut map2 = BiMap::new();
    map2.insert(10usize, -10i32);

    let s1 = NonGenericStruct {
        map1: map1.clone(),
        map2: map2.clone(),
    };
    let s2 = GenericStruct {
        map1: map1.clone(),
        map2: map2.clone(),
    };
    println!("s1 = {:?}", s1); // ok
    println!("s2 = {:?}", s2); // ERROR because `derive(Debug)` fails
}

Some trait bounds in impl<...> Debug for BiHashMap<...> seem unnecessary to implement Debug. I think this prevents #[derive(Debug)].

impl<L, R, LS, RS> fmt::Debug for BiHashMap<L, R, LS, RS>
where
    L: fmt::Debug + Eq + Hash,
    //              ^^^^^^^^^ this seems unnecessary to implement Debug
    R: fmt::Debug + Eq + Hash,
    //              ^^^^^^^^^ this seems unnecessary to implement Debug
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
...
    }
}

Can you remove these trait bounds? I think this improves usability furthermore.

[billyrieger]

You're right. I think the Eq + Hash bounds might have been leftover from an earlier implementation of fmt::Debug.

[atomicky]

Thank you very much!