I'm not a huge fan of Optional.matching (also commonly called Optional.filter) because you may want to "filter" non-optionals as well, i.e. T -> Optional<T> given a predicate. Unfortunately Swift doesn't (yet?) allow writing extensions on any generic T and the alternatives are a free function and an Optional initialiser, neither of which allows you to easily chain them. (Another alternative is a custom operator, but let's not.)

So perhaps the best we can do is Optional.matching as defined in the post, combined with turning a non-optional into an optional using Optional(...) in case we want to "filter" non-optional values using a predicate.