Special-case diagnostic for when you just need @unknown default
#21695
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This is a new feature of Swift 5 mode, so it deserves at least a
little bit of explanation right in the diagnostic. If you have an
otherwise-fully-covered switch but can't assume the enum is frozen,
you'll now get this message:
switch covers known cases, but 'MusicGenre' may have additional
unknown values
Furthermore, if the enum comes from a system header, it looks like
this:
switch covers known cases, but 'NSMusicGenre' may have additional
unknown values, possibly added in future versions
...to further suggest the idea that even though your switch is covered
/now/, it might not handle everything in the /future/. This extra bit
is limited to system headers to avoid showing up on C enums defined in
your own project, for which it sounds silly. (The main message is
still valid though, since you can cram whatever you want into a C
enum, and people use this pattern to implement "private cases".)
rdar://problem/39367045
|
@swift-ci Please test |
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Jan 8, 2019
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Jan 8, 2019
…iftlang#21695) This is a new feature of Swift 5 mode, so it deserves at least a little bit of explanation right in the diagnostic. If you have an otherwise-fully-covered switch but can't assume the enum is frozen, you'll now get this message: switch covers known cases, but 'MusicGenre' may have additional unknown values Furthermore, if the enum comes from a system header, it looks like this: switch covers known cases, but 'NSMusicGenre' may have additional unknown values, possibly added in future versions ...to further suggest the idea that even though your switch is covered /now/, it might not handle everything in the /future/. This extra bit is limited to system headers to avoid showing up on C enums defined in your own project, for which it sounds silly. (The main message is still valid though, since you can cram whatever you want into a C enum, and people use this pattern to implement "private cases".) rdar://problem/39367045 (cherry picked from commit 4a8f81d)
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This is a new feature of Swift 5 mode, so it deserves at least a little bit of explanation right in the diagnostic. If you have an otherwise-fully-covered switch but can't assume the enum is frozen, you'll now get this message:
Furthermore, if the enum comes from a system header, it looks like this:
...to further suggest the idea that even though your switch is covered now, it might not handle everything in the future. This extra bit is limited to system headers to avoid showing up on C enums defined in your own project, for which it sounds silly. (The main message is still valid though, since you can cram whatever you want into a C enum, and people use this pattern to implement "private cases".)
rdar://problem/39367045