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rustrust-tokio

How to move a range of elements from BytesMut?

I have a method that takes a mutable instance of BytesMut. I want to move chunks of it into other instances of BytesMut but am not sure about the syntax to do so. Are there any examples out there?

Solution

  • You could use the range operator on the original buf to move things around or split_off based on some offset value. For example:

    use bytes::{BufMut, BytesMut};

fn main() {
    let mut buf = BytesMut::with_capacity(64);
    let mut buf_to = BytesMut::with_capacity(64);

    buf.put_u8(b't');
    buf.put_u8(b'e');
    buf.put_u8(b's');
    buf.put_u8(b't');

    // move last 2 elements
    buf_to.put(&buf[2..]);
    println!("{:#?}", buf_to); // b"st"

    // You can also split_off the original value
    let mut another_buf = buf.split_off(2);
    println!("{:#?}", another_buf); // b"st"
    println!("{:#?}", buf); // b"te"
}