How do I implement a trait I don't own for a type I don't own?

Question

I wanted to implement the Shl trait for Vec, the code is below. This would make things like vec << 4 possible, which would be ni

Answer 1

While you can't do that exactly, the usual workaround is to just wrap the type you want in your own type and implement the trait on that.

use somecrate::FooType;
use somecrate::BarTrait;

struct MyType(FooType);

impl BarTrait for MyType {
    fn bar(&self) {
        // use `self.0` here
    }
}