Test equality between trait objects

This crate provides a DynEq trait that can be used in trait objects, which permit comparing trait objects. If the two objects are instances of different structs, they will always be not equal. If they are instances of the same struct, the struct's Eq will be used.

Todos

Here's a list of things that could be done and could be nice to have, but I'll implement them only if someone ask: [ ] Permit having PartialEq without Eq (implementation on Box<dyn Trait> will follow) [ ] Implement this for &dyn Trait (permit no-alloc feature)

Example

```rust use dyn_eq::DynEq;

trait MyTrait: DynEq {} dyneq::eqtrait_object!(MyTrait);

impl MyTrait for u8 {} impl MyTrait for u16 {}

let a: Box = Box::new(5u8); let a_bis: Box = Box::new(5u8); let b: Box = Box::new(10u8); let c: Box = Box::new(5u16); let d: Box = Box::new(10u16);

// Same type, same value assert!(a == a_bis); // Same type, different value assert!(a != b); // Different type, different value assert!(a != d); // Different type, same value // Even if the value is the same, the fact that it's a diffrent type means it's not equal assert!(a != c); ```