This adds a pair of Swift protocols that represents C++ iterator types conforming to `std::contiguous_iterator_tag` requirements. These are random access iterators that guarantee that the values are stored in consequent memory addresses.
This will be used to optimize usage of C++ containers such as `std::vector` from Swift, for instance, by providing an overload of `withContiguousStorageIfAvailable` for contiguous containers.
rdar://137877849
Keep the `@_borrowed` attributes on UnsafeCxx[Mutable]Iterator — it appears to be required with the new pointer types. (That’ll need some separate investigation.)
rdar://125146418
[stdlib] Pull back @_aeic on pointer → integer conversions
[stdlib] UnsafeMutablePointer.allocate: Fix thinko
[stdlib] Disable support for noncopyable pointees on some pointer operations
We have to temporarily pull back support for noncopyable pointees for UnsafeMutablePointer.initialize(to:), .moveInitialize, .moveUpdate, as the builtins they’re calling are no longer accepting such types.
These will return following a builtin audit.
[stdlib] Remove workarounds for certain builtins not supporting noncopyable use
https://github.com/apple/swift/pull/71733 fixed this!
[stdlib] Update FIXME
[stdlib] UnsafePointer: Update Swift version numbers
[stdlib] UnsafePointer: Actually hide legacy ABI
[stdlib] Remove workaround for U[M]BP.withMemoryRebound
This will be used to provide a safe overload of `std::vector::erase` in Swift.
`std::vector::erase` is not currently imported into Swift because it returns a C++ iterator.
rdar://113704853
This is currently a no-op since we don't auto-conform custom types to any kind of `MutableCollection` protocols: `UnsafeCxxMutableInputIterator` is only used for `std::map` conformance to `CxxDictionary` in the overlay. However, this will be useful in the future if we start conforming mutable C++ containers to certain Swift protocols: that way containers that use raw non-const pointers as iterators would be treated as mutable in Swift.
This is an inheritor of the existing `UnsafeCxxInputIterator` protocol, with the only difference being the ability to mutate `var pointee` via a non-const `operator*()`.
This is needed to support mutable subscripts for `std::map` via `CxxDictionary`.
rdar://105399019
Since the unsafe iterator types are now used throughout the overlay, not just by `CxxSequence` and `CxxRandomAccessCollection`, let's move them to a separate file.
