Rust: What is the difference between split_off and truncate?

split_off — split at index. truncate — keep first N.

split_off:

• Split into two.
• Returns new Vec.
• Both parts kept.

truncate:

• Keep first N.
• Drop rest.
• Single Vec.

1let mut v = vec![1, 2, 3, 4, 5];
2let rest = v.split_off(2);
3// v: [1, 2], rest: [3, 4, 5]
4
5let mut v = vec![1, 2, 3, 4, 5];
6v.truncate(3);
7// v: [1, 2, 3]

Key: split_off for splitting, truncate for shortening.