Until we get an optimizer pass to remove get/set pairs, passing a
property that is a protocol requirement as inout from generic code is
always going to cause an extra retain, causing many unintended Array
copies.
Because this dropped reference counts to 1 in some cases, it exercised
previously-untested code paths and uncovered bugs, particularly in the
handling of subrange replacement on Slice<T>.
There are still differences in speed for short arrays of CGPoint that bear
investigation, but at least as things scale up, the ratio of time goes
to 1.
Fixes <rdar://problem/17040913> append and += on an array have
completely different performance
Swift SVN r19228
Because _demandUniqueMutableBuffer returns nil if the buffer already
exists, rename to _createUniqueMutableBuffer.
Because _requestUniqueMutableBuffer may return native backing storage
for a slice whose bounds don't exactly match the backing storage, rename
to _requestUniqueMutableBackingBuffer
Swift SVN r19214
Keep calm: remember that the standard library has many more public exports
than the average target, and that this contains ALL of them at once.
I also deliberately tried to tag nearly every top-level decl, even if that
was just to explicitly mark things @internal, to make sure I didn't miss
something.
This does export more than we might want to, mostly for protocol conformance
reasons, along with our simple-but-limiting typealias rule. I tried to also
mark things private where possible, but it's really going to be up to the
standard library owners to get this right. This is also only validated
against top-level access control; I haven't fully tested against member-level
access control yet, and none of our semantic restrictions are in place.
Along the way I also noticed bits of stdlib cruft; to keep this patch
understandable, I didn't change any of them.
Swift SVN r19145
so I took the liberty to 'privatize' them with a leading underscore.
This also completely removes '_ArrayBody' from the public interface.
Should be NFC, apart from the public interface change.
Swift SVN r18625
There's a bit of a reshuffle of the ExplicitCastExpr subclasses:
- The existing ConditionalCheckedCastExpr expression node now represents
"as?".
- A new ForcedCheckedCastExpr node represents "as" when it is a
downcast.
- CoerceExpr represents "as" when it is a coercion.
- A new UnresolvedCheckedCastExpr node describes "as" before it has
been type-checked down to ForcedCheckedCastExpr or CoerceExpr. This
wasn't a strictly necessary change, but it helps us detangle what's
going on.
There are a few new diagnostics to help users avoid getting bitten by
as/as? mistakes:
- Custom errors when a forced downcast (as) is used as the operand
of postfix '!' or '?', with Fix-Its to remove the '!' or make the
downcast conditional (with as?), respectively.
- A warning when a forced downcast is injected into an optional,
with a suggestion to use a conditional downcast.
- A new error when the postfix '!' is used for a contextual
downcast, with a Fix-It to replace it with "as T" with the
contextual type T.
Lots of test updates, none of which felt like regressions. The new
tests are in test/expr/cast/optionals.swift.
Addresses <rdar://problem/17000058>
Swift SVN r18556
assert() and fatalError()
These functions are meant to be used in user code. They are enabled in debug
mode and disabled in release or fast mode.
_precondition() and _preconditionFailure()
These functions are meant to be used in library code to check preconditions at
the api boundry. They are enabled in debug mode (with a verbose message) and
release mode (trap). In fast mode they are disabled.
_debugPrecondition() and _debugPreconditionFailure()
These functions are meant to be used in library code to check preconditions that
are not neccesarily comprehensive for safety (UnsafePointer can be null or an
invalid pointer but we can't check both). They are enabled only in debug mode.
_sanityCheck() and _fatalError()
These are meant to be used for internal consistency checks. They are only
enabled when the library is build with -DSWIFT_STDLIB_INTERNAL_CHECKS=ON.
I modified the code in the standard library to the best of my judgement.
rdar://16477198
Swift SVN r18212
