You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: ops.rs
    path of file: ./repos/juice/rust-blas/src/vector
    
    the code of the file until where you have to start completion: // Copyright 2014
    
    fn slice() {
        let mut x = [1f32, -2f32, 3f32, 4f32];
        let mut y = [2f32, -3f32, 4f32, 1f32];
        let xr = [2f32, -3f32, 4f32, 1f32];
        let yr = [1f32, -2f32, 3f32, 4f32];

        Swap::swap(&mut x[..], &mut y[..]);
        assert_eq!(x, xr);
        assert_eq!(y, yr);
    }