retain_mut 0.1.0

Provide retain_mut method that has the same functionality as retain but gives mutable borrow to the predicate.


Trait that provides retain_mut method.

This method is basically the same as Vec::retain, but it gives mutable borrow to the predicate function.

This was probably a historical mistake in Rust library, that retain should do this at the very beginning. See rust-lang/rust#25477.

It currently only implements retain_mut for Vec. We may implement it for more collection types in the future.