**Object-safe traits** are traits with methods that follow these two rules:
- the return type is not `Self`
- there are no generic types parameters

> `Self` is an alias for the type we will be implementing the trait on.

Only object-safe traits can be made into trait objects. To learn more about creating trait objects, check out this [answer](https://www.educative.io/answers/what-is-the-dyn-keyword-in-rust).

# Example

Below are two examples of traits, one that is object-safe and one that is not.

&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; An object-safe trait
```rust
pub trait Area {
    /// Returns area as i32 (32-bit
    /// integer)
    fn area(&self) -> i32;
}


&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Not an object-safe trait
```rust
pub trait Clone {
    /// Returns a clone (duplicate)
    /// of the object
    fn clone(&self) -> Self;
}

The reason why the `Clone` trait on the right is not object-safe is because the signature of its `clone` method returns `Self`.

For more details on why object-safety is required for trait objects, check out the [official docs](https://doc.rust-lang.org/book/ch17-02-trait-objects.html#object-safety-is-required-for-trait-objects).

What are object safe traits in Rust?

Object-safe traits in Rust have methods without Self return types or generic parameters, enabling trait objects.