Add function application to Swift's standard library

[Jens]

@ExFalsoQuodlibet

My current opinion, based on my research and experience, is that the best possible solution here is to add to Swift an implicit .apply member (possibly with a different name, I'd prefer .to ) with compiler support.

If an implicit .to(…) member should be added, then perhaps also an implicit .with(…)?

As previously discussed here:

@ExFalsoQuodlibet

For example, in pseudo-swift:

extension Any {
    func with(_ modify: (inout Self) throws -> Void) rethrows -> Self {
        var copy = self
        try modify(&copy)
        return copy
    }
}