Rust: What is the difference between sort and sort_by?

sort — default ordering. sort_by — custom comparator.

sort:

• Default ordering.
• Requires Ord.
• Simple.

sort_by:

• Custom comparator.
• Flexible.
• For complex sorting.

1let mut v = vec![3, 1, 4, 1, 5];
2v.sort();
3// [1, 1, 3, 4, 5]
4
5let mut v = vec![3, 1, 4, 1, 5];
6v.sort_by(|a, b| b.cmp(a));  // Descending
7// [5, 4, 3, 1, 1]

Key: sort for default, sort_by for custom.