Small cleanup: Use () -> ... instead of (Void) -> ... for no-argument closures #984
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… closures In Swift, (Void) -> Void is actually a function that takes a single value of empty-tuple type, and not a function that takes no arguments. Swift 3 largely ignored the distinction because of the implicit 'tuple splat' behavior; in Swift 4, this behavior has been eliminated as part of implementing SE-0110, so calling a function of type (Void) -> () now requires passing in an empty tuple, like foo(()). I believe this is not intended behavior, so this patch changes the functions in question to be written as () -> Void.
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@parkera Does this look OK? |
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Yup, thanks. |
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@slavapestov how are you able to build |
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@mattrajca Could you confirm the platform you're building for? Ubuntu 16.10? I haven't seen NSGeometry errors you described in the email. Are you using the swift/util/build script - or maybe you're building against a snapshot somehow? |
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@e78l I am using |
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@mattrajca #988 is expected to fix the build errors on macOS (this thread) |
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I think this is can be merged. It will eliminate a warning that we're seeing in the Foundation builds. |
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@swift-ci please test and merge |
In Swift, (Void) -> Void is actually a function that takes
a single value of empty-tuple type, and not a function that
takes no arguments.
Swift 3 largely ignored the distinction because of the implicit
'tuple splat' behavior; in Swift 4, this behavior has been
eliminated as part of implementing SE-0110, so calling a function
of type (Void) -> () now requires passing in an empty tuple,
like foo(()).
I believe this is not intended behavior, so this patch changes
the functions in question to be written as () -> Void.