Changes relevant to competitive programming:

• New sort implementations Both the stable and unstable sort implementations in the standard library have been updated to new algorithms, improving their runtime performance and compilation time. Additionally, both of the new sort algorithms try to detect incorrect implementations of Ord that prevent them from being able to produce a meaningfully sorted result, and will now panic on such cases rather than returning effectively randomly arranged data. Users encountering these panics should audit their ordering implementations to ensure they satisfy the requirements documented in PartialOrd and Ord.

• Duration::abs_diff stabilized