Complete the signature and the body of the `str_len` that receives a string or a string literal and returns its length without taking ownership of the value (i.e, borrowing the value)
Complete the signature and the body of the `str_len`**function**that receives a string or a string literal and returns its length without taking ownership of the value (i.e, borrowing the value).
### Expected Function
### Expected Function (The signature needs to be completed)
```rust
pub fn str_len(s: ) -> usize {
}
```
### Notions
[Primitive Type str](https://doc.rust-lang.org/std/primitive.str.html)
