id-as-Any lets you pass Optional to an ObjC API that takes `nonnull id`, and also lets you bridge containers of `Optional` to `NSArray` etc. When this occurs, we can unwrap the value and bridge it so that inhabited optionals still pass into ObjC in the expected way, but we need something to represent `none` other than the `nil` pointer. Cocoa provides `NSNull` as the canonical "null for containers" object, which is the least bad of many possible answers. If we happen to have the rare nested optional `T??`, there is no precedented analog for these in Cocoa, so just generate a unique sentinel object to preserve the `nil`-ness depth so we at least don't lose information round-tripping across the ObjC-Swift bridge.
Making Optional conform to _ObjectiveCBridgeable is more or less enough to make this all work, though there are a few additional edge case things that need to be fixed up. We don't want to accept `AnyObject??` as an @objc-compatible type, so special-case Optional in `getForeignRepresentable`.
Implements SR-0140 (rdar://problem/27905315).
id-as-Any lets you pass Optional to an ObjC API that takes `nonnull id`, and also lets you bridge containers of `Optional` to `NSArray` etc. When this occurs, we can unwrap the value and bridge it so that inhabited optionals still pass into ObjC in the expected way, but we need something to represent `none` other than the `nil` pointer. Cocoa provides `NSNull` as the canonical "null for containers" object, which is the least bad of many possible answers. If we happen to have the rare nested optional `T??`, there is no precedented analog for these in Cocoa, so just generate a unique sentinel object to preserve the `nil`-ness depth so we at least don't lose information round-tripping across the ObjC-Swift bridge.
Making Optional conform to _ObjectiveCBridgeable is more or less enough to make this all work, though there are a few additional edge case things that need to be fixed up. We don't want to accept `AnyObject??` as an @objc-compatible type, so special-case Optional in `getForeignRepresentable`.
Implements SR-0140 (rdar://problem/27905315).
change includes both the necessary protocol updates and the deprecation
warnings
suitable for migration. A future patch will remove the renamings and
make this
a hard error.
Being generic, the '_unwrapped' intrinsics force trafficking through memory, and while they're transparent so always get inlined, we don't do memory promotion in -Onone. Emitting the branch inline lets loadable optionals stay values leading to better -Onone codegen. (It also lets us throw away a surprising amount of support code for these optional intrinsics.)
We already have detailed knowledge of Optional's layout in SILGen, so these intrinsics were almost unused. They were only used in a few obscure places by some optional-to-bool conversions, used by 'is [A]' collection tests and the codegen for 'lazy' properties. Change these over to generate an EnumIsCaseExpr that we can directly lower to a 'select_enum' instruction in SILGen, leading to better codegen and obviating the need for these intrinsic functions.
This will generate significantly better code if a generic optional is compared against nil.
In a generic function this ended up with a call to the == function. Now, due to mandatory inlining, it boils down to a switch_enum.
This documentation revision covers a large number of types & protocols:
String, its views and their indices, the Unicode codec types and protocol,
as well as Character, UnicodeScalar, and StaticString, among others.
This also includes a few small changes across the standard library for
consistency.
This revises and expands on documentation for the new collection methods
for working with indices and the revised Swift 3 set APIs. In addition,
it includes documentation for the new range types.
Optional's Mirror (the default one) used to report the display style as
"enum", which is technically correct, but we have a more specific style
for Optional.
<rdar://problem/24450196>
This is a staging attribute that will eventually mean "fixed-contents"
for structs and "closed" for enums, as described in
docs/LibraryEvolution.rst.
This is pretty much the minimal set of types that must be fixed-layout,
because SILGen makes assumptions about their lowering.
If desired, some SILGen refactoring can allow some of these to be
resilient. For example, bridging value types could be made to work
with resilient types.
This pull request broke the following tests on several build configurations
(eg --preset=buildbot,tools=RA,stdlib=DA)
1_stdlib/Reflection.swift
1_stdlib/ReflectionHashing.swift
1_stdlib/UnsafePointer.swift.gyb
This reverts commit c223a3bf06, reversing
changes made to 5c2bb09b09.
Changes:
- Reverted commit reverting original SR-88 commit
- Removed mirror children helper collections and related code
- Rewrote some tests to keep them working properly
- Wrote two more tests for the three pointer APIs to ensure no crashes if created using a value > Int64.max
This reverts commit 8917eb0e5a.
