mirror of
https://github.com/apple/swift.git
synced 2025-12-21 12:14:44 +01:00
[String] Drop in initial UTF-8 String prototype
This is a giant squashing of a lot of individual changes prototyping a switch of String in Swift 5 to be natively encoded as UTF-8. It includes what's necessary for a functional prototype, dropping some history, but still leaves plenty of history available for future commits. My apologies to anyone trying to do code archeology between this commit and the one prior. This was the lesser of evils.
This commit is contained in:
Michael Ilseman
@@ -12,308 +12,288 @@
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import SwiftShims
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// TODO(UTF8): We can drop the nonobjc annotations soon
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@_fixed_layout
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@usableFromInline
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class _SwiftRawStringStorage : __SwiftNativeNSString {
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@nonobjc
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@usableFromInline
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final var capacity: Int
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@nonobjc
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@usableFromInline
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final var count: Int
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@nonobjc
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internal init(_doNotCallMe: ()) {
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_sanityCheckFailure("Use the create method")
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}
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@inlinable
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@nonobjc
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internal var rawStart: UnsafeMutableRawPointer {
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_abstract()
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}
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@inlinable
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@nonobjc
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final var unusedCapacity: Int {
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_sanityCheck(capacity >= count)
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return capacity - count
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}
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@objc
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internal class _AbstractStringStorage: _SwiftNativeNSString, _NSStringCore {
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// Abstract interface
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internal var asString: String { get { Builtin.unreachable() } }
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internal var count: Int { get { Builtin.unreachable() } }
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}
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internal typealias _ASCIIStringStorage = _SwiftStringStorage<UInt8>
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@usableFromInline // FIXME(sil-serialize-all)
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internal typealias _UTF16StringStorage = _SwiftStringStorage<UTF16.CodeUnit>
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@_fixed_layout
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@usableFromInline
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final class _SwiftStringStorage<CodeUnit>
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: _SwiftRawStringStorage, _NSStringCore
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where CodeUnit : UnsignedInteger & FixedWidthInteger {
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/// Create uninitialized storage of at least the specified capacity.
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@usableFromInline
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@nonobjc
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@_specialize(where CodeUnit == UInt8)
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@_specialize(where CodeUnit == UInt16)
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internal static func create(
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capacity: Int,
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count: Int = 0
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) -> _SwiftStringStorage<CodeUnit> {
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_sanityCheck(count >= 0 && count <= capacity)
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#if arch(i386) || arch(arm)
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#else
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// TODO(SR-7594): Restore below invariant
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// _sanityCheck(
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// CodeUnit.self != UInt8.self || capacity > _SmallUTF8String.capacity,
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// "Should prefer a small representation")
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#endif // 64-bit
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let storage = Builtin.allocWithTailElems_1(
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_SwiftStringStorage<CodeUnit>.self,
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capacity._builtinWordValue, CodeUnit.self)
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let storageAddr = UnsafeMutableRawPointer(
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Builtin.bridgeToRawPointer(storage))
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let endAddr = (
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storageAddr + _swift_stdlib_malloc_size(storageAddr)
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).assumingMemoryBound(to: CodeUnit.self)
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storage.capacity = endAddr - storage.start
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storage.count = count
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_sanityCheck(storage.capacity >= capacity)
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return storage
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}
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@inlinable
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@nonobjc
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internal override final var rawStart: UnsafeMutableRawPointer {
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return UnsafeMutableRawPointer(start)
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}
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// ObjC interfaces
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#if _runtime(_ObjC)
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// NSString API
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@objc(initWithCoder:)
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@usableFromInline
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convenience init(coder aDecoder: AnyObject) {
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_sanityCheckFailure("init(coder:) not implemented for _SwiftStringStorage")
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}
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extension _AbstractStringStorage {
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@objc(length)
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@usableFromInline
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var length: Int {
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return count
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}
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final internal var length: Int { return asString._utf16Length() }
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@objc(characterAtIndex:)
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@usableFromInline
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func character(at index: Int) -> UInt16 {
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defer { _fixLifetime(self) }
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precondition(index >= 0 && index < count, "Index out of bounds")
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return UInt16(start[index])
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final func character(at index: Int) -> UInt16 {
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return asString._utf16CodeUnitAtOffset(index)
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}
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@objc(getCharacters:range:)
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@usableFromInline
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func getCharacters(
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_ buffer: UnsafeMutablePointer<UInt16>,
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range aRange: _SwiftNSRange
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) {
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final func getCharacters(
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_ buffer: UnsafeMutablePointer<UInt16>,
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range aRange: _SwiftNSRange) {
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_precondition(aRange.location >= 0 && aRange.length >= 0,
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"Range out of bounds")
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_precondition(aRange.location + aRange.length <= Int(count),
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"Range out of bounds")
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let slice = unmanagedView[
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aRange.location ..< aRange.location + aRange.length]
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slice._copy(
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into: UnsafeMutableBufferPointer<UTF16.CodeUnit>(
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start: buffer,
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count: aRange.length))
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_fixLifetime(self)
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let range = Range(
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uncheckedBounds: (aRange.location, aRange.location+aRange.length))
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let slice = asString.utf16[asString._utf16OffsetToIndex(range)]
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let outputBufPtr = UnsafeMutableBufferPointer(
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start: buffer, count: range.count)
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let _ = slice._copyContents(initializing: outputBufPtr)
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}
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@objc(_fastCharacterContents)
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@usableFromInline
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func _fastCharacterContents() -> UnsafePointer<UInt16>? {
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guard CodeUnit.self == UInt16.self else { return nil }
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return UnsafePointer(rawStart.assumingMemoryBound(to: UInt16.self))
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final func _fastCharacterContents() -> UnsafePointer<UInt16>? {
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return nil
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}
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@objc(_fastCStringContents)
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final func _fastCStringContents() -> UnsafePointer<CChar>? {
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if let native = self as? _StringStorage {
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return native.start._asCChar
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}
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// TODO(UTF8 perf): shared from literals are nul-terminated...
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return nil
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}
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@objc(copyWithZone:)
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@usableFromInline
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func copy(with zone: _SwiftNSZone?) -> AnyObject {
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// While _SwiftStringStorage instances aren't immutable in general,
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final func copy(with zone: _SwiftNSZone?) -> AnyObject {
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// While _StringStorage instances aren't immutable in general,
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// mutations may only occur when instances are uniquely referenced.
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// Therefore, it is safe to return self here; any outstanding Objective-C
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// reference will make the instance non-unique.
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return self
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}
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}
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#endif // _runtime(_ObjC)
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}
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extension _SwiftStringStorage {
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// Basic properties
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@inlinable
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@_fixed_layout
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@usableFromInline
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final internal class _StringStorage: _AbstractStringStorage {
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@nonobjc
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internal final var start: UnsafeMutablePointer<CodeUnit> {
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return UnsafeMutablePointer(Builtin.projectTailElems(self, CodeUnit.self))
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@usableFromInline
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internal var capacity: Int
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@nonobjc
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@usableFromInline
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internal var _count: Int
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@nonobjc
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@inlinable
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override internal var count: Int { @inline(__always) get { return _count } }
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@nonobjc
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@inlinable
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override internal var asString: String {
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@inline(__always) get { return String(_StringGuts(self)) }
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}
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@inlinable
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@nonobjc
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internal final var end: UnsafeMutablePointer<CodeUnit> {
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return start + count
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}
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@inlinable
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@nonobjc
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internal final var capacityEnd: UnsafeMutablePointer<CodeUnit> {
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return start + capacity
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}
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@inlinable
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@nonobjc
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var usedBuffer: UnsafeMutableBufferPointer<CodeUnit> {
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return UnsafeMutableBufferPointer(start: start, count: count)
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}
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@inlinable
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@nonobjc
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var unusedBuffer: UnsafeMutableBufferPointer<CodeUnit> {
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@inline(__always)
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get {
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return UnsafeMutableBufferPointer(start: end, count: capacity - count)
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}
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}
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@inlinable
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@nonobjc
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var unmanagedView: _UnmanagedString<CodeUnit> {
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return _UnmanagedString(start: self.start, count: self.count)
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internal init(_doNotCallMe: ()) {
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_sanityCheckFailure("Use the create method")
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}
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}
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extension _SwiftStringStorage {
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// Append operations
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// Creation
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extension _StringStorage {
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@nonobjc
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internal final func _appendInPlace<OtherCodeUnit>(
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_ other: _UnmanagedString<OtherCodeUnit>
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)
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where OtherCodeUnit : FixedWidthInteger & UnsignedInteger {
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let otherCount = Int(other.count)
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_sanityCheck(self.count + otherCount <= self.capacity)
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other._copy(into: self.unusedBuffer)
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self.count += otherCount
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internal static func create(
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capacity: Int, count: Int = 0
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) -> _StringStorage {
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_sanityCheck(capacity >= count)
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// Reserve enough capacity for a trailing nul character
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let capacity = 1 + Swift.max(capacity, _SmallUTF8String.capacity)
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_sanityCheck(capacity > count)
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let storage = Builtin.allocWithTailElems_1(
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_StringStorage.self,
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capacity._builtinWordValue, UInt8.self)
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let storageAddr = UnsafeRawPointer(
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Builtin.bridgeToRawPointer(storage))
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let endAddr = (
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storageAddr + _stdlib_malloc_size(storageAddr)
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).assumingMemoryBound(to: UInt8.self)
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storage.capacity = endAddr - storage.start
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storage._count = count
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_sanityCheck(storage.capacity >= capacity)
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storage.unusedStorage[0] = 0 // nul-terminated
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storage._invariantCheck()
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return storage
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}
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@nonobjc
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internal final func _appendInPlace(_ other: _UnmanagedOpaqueString) {
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let otherCount = Int(other.count)
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_sanityCheck(self.count + otherCount <= self.capacity)
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other._copy(into: self.unusedBuffer)
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self.count += otherCount
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internal static func create(
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initializingFrom bufPtr: UnsafeBufferPointer<UInt8>, capacity: Int
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) -> _StringStorage {
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_sanityCheck(capacity >= bufPtr.count)
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let storage = _StringStorage.create(
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capacity: capacity, count: bufPtr.count)
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let addr = bufPtr.baseAddress._unsafelyUnwrappedUnchecked
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storage.mutableStart.initialize(from: addr, count: bufPtr.count)
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return storage
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}
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@nonobjc
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internal final func _appendInPlace<C: Collection>(contentsOf other: C)
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where C.Element == CodeUnit {
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let otherCount = Int(other.count)
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_sanityCheck(self.count + otherCount <= self.capacity)
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var (remainder, writtenUpTo) =
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other._copyContents(initializing: self.unusedBuffer)
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_precondition(remainder.next() == nil, "Collection underreported its count")
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_precondition(writtenUpTo == otherCount, "Collection misreported its count")
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count += otherCount
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internal static func create(
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initializingFrom bufPtr: UnsafeBufferPointer<UInt8>
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) -> _StringStorage {
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return _StringStorage.create(
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initializingFrom: bufPtr, capacity: bufPtr.count)
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}
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@_specialize(where C == Character._SmallUTF16, CodeUnit == UInt8)
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@nonobjc
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internal final func _appendInPlaceUTF16<C: Collection>(contentsOf other: C)
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where C.Element == UInt16 {
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let otherCount = Int(other.count)
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_sanityCheck(self.count + otherCount <= self.capacity)
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// TODO: Use _copyContents(initializing:) for UTF16->UTF16 case
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var it = other.makeIterator()
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for p in end ..< end + otherCount {
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p.pointee = CodeUnit(it.next()!)
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}
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_precondition(it.next() == nil, "Collection underreported its count")
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count += otherCount
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internal static func create(
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initializingFrom bufPtr: UnsafeBufferPointer<UInt8>,
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andAppending secondBufPtr: UnsafeBufferPointer<UInt8>
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) -> _StringStorage {
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let size = bufPtr.count + secondBufPtr.count
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let storage = _StringStorage.create(
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capacity: size, count: size)
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let addr = bufPtr.baseAddress._unsafelyUnwrappedUnchecked
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storage.mutableStart.initialize(from: addr, count: bufPtr.count)
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let secondAddr = secondBufPtr.baseAddress._unsafelyUnwrappedUnchecked
|
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(storage.mutableStart + bufPtr.count).initialize(
|
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from: secondAddr, count: secondBufPtr.count)
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return storage
|
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}
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}
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extension _SwiftStringStorage {
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@nonobjc
|
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internal final func _appendInPlace(_ other: _StringGuts, range: Range<Int>) {
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if _slowPath(other._isOpaque) {
|
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_opaqueAppendInPlace(opaqueOther: other, range: range)
|
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return
|
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}
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// TODO(UTF8 perf): Append helpers, which can keep nul-termination
|
||||
|
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defer { _fixLifetime(other) }
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||||
if other.isASCII {
|
||||
_appendInPlace(other._unmanagedASCIIView[range])
|
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} else {
|
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_appendInPlace(other._unmanagedUTF16View[range])
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// Usage
|
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extension _StringStorage {
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@nonobjc
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@inlinable
|
||||
internal var mutableStart: UnsafeMutablePointer<UInt8> {
|
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@inline(__always) get {
|
||||
return UnsafeMutablePointer(Builtin.projectTailElems(self, UInt8.self))
|
||||
}
|
||||
}
|
||||
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@usableFromInline // @opaque
|
||||
internal final func _opaqueAppendInPlace(
|
||||
opaqueOther other: _StringGuts, range: Range<Int>
|
||||
) {
|
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_sanityCheck(other._isOpaque)
|
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if other._isSmall {
|
||||
other._smallUTF8String[range].withUnmanagedUTF16 {
|
||||
self._appendInPlace($0)
|
||||
}
|
||||
return
|
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}
|
||||
defer { _fixLifetime(other) }
|
||||
_appendInPlace(other._asOpaque()[range])
|
||||
@nonobjc
|
||||
@inlinable
|
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internal var mutableEnd: UnsafeMutablePointer<UInt8> {
|
||||
@inline(__always) get { return mutableStart + count }
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
internal final func _appendInPlace(_ other: _StringGuts) {
|
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if _slowPath(other._isOpaque) {
|
||||
_opaqueAppendInPlace(opaqueOther: other)
|
||||
return
|
||||
}
|
||||
|
||||
defer { _fixLifetime(other) }
|
||||
if other.isASCII {
|
||||
_appendInPlace(other._unmanagedASCIIView)
|
||||
} else {
|
||||
_appendInPlace(other._unmanagedUTF16View)
|
||||
}
|
||||
}
|
||||
|
||||
@usableFromInline // @opaque
|
||||
internal final func _opaqueAppendInPlace(opaqueOther other: _StringGuts) {
|
||||
_sanityCheck(other._isOpaque)
|
||||
if other._isSmall {
|
||||
other._smallUTF8String.withUnmanagedUTF16 {
|
||||
self._appendInPlace($0)
|
||||
}
|
||||
return
|
||||
}
|
||||
defer { _fixLifetime(other) }
|
||||
_appendInPlace(other._asOpaque())
|
||||
@inlinable
|
||||
internal var start: UnsafePointer<UInt8> {
|
||||
@inline(__always) get { return UnsafePointer(mutableStart) }
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
internal final func _appendInPlace(_ other: String) {
|
||||
self._appendInPlace(other._guts)
|
||||
@inlinable
|
||||
internal final var end: UnsafePointer<UInt8> {
|
||||
@inline(__always) get { return UnsafePointer(mutableEnd) }
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
internal final func _appendInPlace<S : StringProtocol>(_ other: S) {
|
||||
self._appendInPlace(
|
||||
other._wholeString._guts,
|
||||
range: other._encodedOffsetRange)
|
||||
@inlinable
|
||||
internal var codeUnits: UnsafeBufferPointer<UInt8> {
|
||||
@inline(__always) get {
|
||||
return UnsafeBufferPointer(start: start, count: count)
|
||||
}
|
||||
}
|
||||
|
||||
@inlinable
|
||||
@nonobjc
|
||||
internal var unusedStorage: UnsafeMutableBufferPointer<UInt8> {
|
||||
@inline(__always) get {
|
||||
return UnsafeMutableBufferPointer(
|
||||
start: mutableEnd, count: unusedCapacity)
|
||||
}
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
@inlinable
|
||||
internal var unusedCapacity: Int {
|
||||
@inline(__always) get { return capacity &- count }
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
@inlinable @inline(__always)
|
||||
internal func _invariantCheck() {
|
||||
#if INTERNAL_CHECKS_ENABLED
|
||||
let rawSelf = UnsafeRawPointer(Builtin.bridgeToRawPointer(self))
|
||||
let rawStart = UnsafeRawPointer(start)
|
||||
_sanityCheck(rawSelf + Int(_StringObject.nativeBias) == rawStart)
|
||||
_sanityCheck(self.capacity > self.count, "no room for nul-terminator")
|
||||
_sanityCheck(self.unusedStorage[0] == 0, "not nul terminated")
|
||||
#endif
|
||||
}
|
||||
}
|
||||
|
||||
// For bridging literals
|
||||
//
|
||||
// TODO(UTF8): Unify impls with _StringStorage
|
||||
//
|
||||
@_fixed_layout
|
||||
@usableFromInline
|
||||
final internal class _SharedStringStorage: _AbstractStringStorage {
|
||||
@nonobjc
|
||||
@usableFromInline
|
||||
internal var owner: AnyObject?
|
||||
|
||||
@nonobjc
|
||||
@usableFromInline
|
||||
internal var contents: UnsafeBufferPointer<UInt8>
|
||||
|
||||
@nonobjc
|
||||
@usableFromInline
|
||||
internal var start: UnsafePointer<UInt8> {
|
||||
return contents.baseAddress._unsafelyUnwrappedUnchecked
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
@usableFromInline
|
||||
override internal var count: Int { return contents.count }
|
||||
|
||||
@nonobjc
|
||||
internal init(owner: AnyObject, contents bufPtr: UnsafeBufferPointer<UInt8>) {
|
||||
self.owner = owner
|
||||
self.contents = bufPtr
|
||||
super.init()
|
||||
self._invariantCheck()
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
internal init(immortal bufPtr: UnsafeBufferPointer<UInt8>) {
|
||||
self.owner = nil
|
||||
self.contents = bufPtr
|
||||
super.init()
|
||||
self._invariantCheck()
|
||||
}
|
||||
|
||||
@nonobjc
|
||||
override internal var asString: String { return String(_StringGuts(self)) }
|
||||
}
|
||||
|
||||
extension _SharedStringStorage {
|
||||
@nonobjc
|
||||
@inlinable @inline(__always)
|
||||
internal func _invariantCheck() {
|
||||
#if INTERNAL_CHECKS_ENABLED
|
||||
#endif
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
Reference in New Issue
Block a user