vec2.rs - compare addresses of input and output

[Vest]

Hello everyone,

I see that in the exercise the input vector and output vector must be the same (v). I am curious, if the unit test should reflect this: "the addresses of input and output vectors must be equal".

I am asking this, because my colleague, when he was solving the case, has created a new vector and returned it with an explicit "return" statement.

If needed, I can try to create the PR with the additional unit test.

Thanks, Vest