+1 I was just missing this feature as well.
Thanks, Jon > On Feb 22, 2017, at 10:16 AM, Nate Cook via swift-evolution > <[email protected]> wrote: > > Hello all, > > I was surprised to find that I can't use an instance member as the default > value of a method parameter, only constants and the run-time calculated > #file, #line, etc. Is it possible to remove this limitation? > > I'd like to propose that we add an overload of the collection > index(_:offsetBy:) methods that use the collection's startIndex as a default > parameter, but we can't provide that without either this feature or an extra > overload. If the declaration looks like this: > > extension Collection { > func index(_ i: Index = startIndex, offsetBy n: IndexDistance) -> Index { > // ... > } > } > > then calling that method with an omitted first parameter would treat it as > something like this: > > extension Collection { > func index(offsetBy n: IndexDistance) -> Index { > let i = startIndex > // ... > } > } > > Is this just syntactic sugar, or am I missing something that makes this > harder than it looks? I can see how more complex expressions could be useful > there, too, and can't find an obvious reason we couldn't use any code that > could be inserted at the top of the method body. > > Thanks! > Nate > > _______________________________________________ > swift-evolution mailing list > [email protected] > https://lists.swift.org/mailman/listinfo/swift-evolution
_______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
