feature: Derive Hash for KeyboardInput.

[shanecelis]

Objective

Derive Hash for KeyboardInput.

Problem

I was writing code to take crossterm events and republish them as bevy input events. One scenario requires I check if the same key press was happening repeatedly; in a regular terminal we don't get key released events, so I was simulating them.

I was surprised to find that I couldn't put KeyboardInput into a HashSet.

Work Around

My work around was to add a new type that implemented Hash.

#[derive(Deref, DerefMut, PartialEq, Eq)]
struct KeyInput(KeyboardInput);

impl Hash for KeyInput {
    fn hash<H>(&self, state: &mut H)
    where
        H: Hasher,
    {
        self.key_code.hash(state);
        self.logical_key.hash(state);
        self.state.hash(state);
        self.window.hash(state);
    }
}

Solution

A better solution since all members of KeyboardInput implement Hash is to have it derive Hash as well.

Testing

My newtype solution works for its purpose.