Part of ABI FIXME #99, this gives us some nice consistency that
ensures that slicing a SubSequence gives us another SubSequence. There
are two source-compatibility implications to this change:
* Collections now need to satisfy this property, which could not be
expressed in Swift 3. There might be some Collections that don't
satisfy this property, and will break with the Swift 4 compiler
*even in Swift 3 compatibility mode*. Case in point...
* The Lazy collection types were formulated as a lazy collection of
the base slice (e.g., LazyCollection<ArraySlice<T>>) rather than as
a slice of the lazy collection (e.g.,
Slice<LazyCollection<Array<T>>). The former doesn't meet the new
requirements, so change to the latter.
Address ABI FIXME #68 by using same-type constraints directly on an
associated type to describe the requirements on the Indices associated
type of the Collection protocol. ABI FIXMEs #89, #90, #91 are all in
StdlibUnittest, and provoke warnings once #68 is fixed, but it's nice
to clear them out.
Fixes SR-2121.
* [runtime] Fix some casts of _SwiftValue.
* Allow _SwiftValue to be cast to NSObject by yielding the box object itself.
* Failed casts from NSDictionary containing _SwiftValue should not crash.
SR-4306, rdar://31197066
- CYGWIN symbol is used to distinguish Cygwin environment from other OS
and other environment in Windows.
- Added windows and windowsCygnus to OSVersion in StdlibUnittest
* replace unused closure parameters with '_' in stdlib source
* fold some _ closure arguments into line above
* fold more _ closure arguments into line above
Apple and the Swift community has settled on this style:
https://devforums.apple.com/message/1133616#1133616
> FWIW, we've recently decided to standardize on () -> Void
> (generally, () for parameters and Void for return types) across all of our
> documentation.
[test] Add a timeout to runRaceTest(). Use it to limit test AtomicInt.swift.
This cuts AtomicInt.swift's execution time from several hours to
about ten minutes on slow hardware and slow build configurations.
From the Swift documentation:
"If you define an optional variable without providing a default value,
the variable is automatically set to nil for you."
The new names are what people generally expect. The old names made more
sense in the old times when the 'Optional.None' case could not be
created with the 'nil' keyword.
