--- title: Escapable framework: swift role: symbol role_heading: Protocol path: swift/escapable --- # Escapable A type whose values can persist beyond their immediate local scope. ## Declaration ```swift protocol Escapable ``` ## Overview Overview Escapable values can be assigned to global or static variables, returned from functions, captured by escaping closures, and so on. All Swift types implicitly conform to this protocol by default, allowing them to be moved across scopes freely because they lack any lifetime dependencies. In contrast, values of types that suppress their implicit conformance to Escapable (by writing ~Escapable) carry a lifetime dependency. These dependencies ensure the ~Escapable value does not live longer than the value it depends on. Explicit lifetime dependency annotations may be required when working with these types. In generic contexts, ~Escapable works much in the same way as ~Copyable. It allows functions and types to work with values that may or may not be Escapable, and types can be conditionally Escapable based on their generic arguments. A conformance requirement for Escapable is automatically inferred in extensions and for generic type parameters, unless suppressed with ~Escapable. ## Relationships ### Conforming Types - [Anchor](regexbuilder/anchor.md) - [AnyBidirectionalCollection](swift/anybidirectionalcollection.md) - [AnyCollection](swift/anycollection.md) - [AnyHashable](swift/anyhashable.md) - [AnyIterator](swift/anyiterator.md) - [AnyKeyPath](swift/anykeypath.md) - [AnyRandomAccessCollection](swift/anyrandomaccesscollection.md) - [AnyRegexOutput](swift/anyregexoutput.md) - [AnySequence](swift/anysequence.md) - [Array](swift/array.md) - [ArraySlice](swift/arrayslice.md) - [AsyncCompactMapSequence](swift/asynccompactmapsequence.md) - [AsyncDropFirstSequence](swift/asyncdropfirstsequence.md) - [AsyncDropWhileSequence](swift/asyncdropwhilesequence.md) - [AsyncFilterSequence](swift/asyncfiltersequence.md) - [AsyncFlatMapSequence](swift/asyncflatmapsequence.md) - [AsyncMapSequence](swift/asyncmapsequence.md) - [AsyncPrefixSequence](swift/asyncprefixsequence.md) - [AsyncPrefixWhileSequence](swift/asyncprefixwhilesequence.md) - [AsyncStream](swift/asyncstream.md) - [AsyncStream.Continuation](swift/asyncstream/continuation.md) - [AsyncStream.Continuation.Termination](swift/asyncstream/continuation/termination.md) - [AsyncThrowingCompactMapSequence](swift/asyncthrowingcompactmapsequence.md) - [AsyncThrowingDropWhileSequence](swift/asyncthrowingdropwhilesequence.md) - [AsyncThrowingFilterSequence](swift/asyncthrowingfiltersequence.md) - [AsyncThrowingFlatMapSequence](swift/asyncthrowingflatmapsequence.md) - [AsyncThrowingMapSequence](swift/asyncthrowingmapsequence.md) - [AsyncThrowingPrefixWhileSequence](swift/asyncthrowingprefixwhilesequence.md) - [AsyncThrowingStream](swift/asyncthrowingstream.md) - [AsyncThrowingStream.Continuation](swift/asyncthrowingstream/continuation.md) - [AtomicLoadOrdering](synchronization/atomicloadordering.md) - [AtomicStoreOrdering](synchronization/atomicstoreordering.md) - [AtomicUpdateOrdering](synchronization/atomicupdateordering.md) - [AutoreleasingUnsafeMutablePointer](swift/autoreleasingunsafemutablepointer.md) - [Bool](swift/bool.md) - [CVaListPointer](swift/cvalistpointer.md) - [Capture](regexbuilder/capture.md) - [Character](swift/character.md) - [CharacterClass](regexbuilder/characterclass.md) - [ChoiceOf](regexbuilder/choiceof.md) - [ClosedRange](swift/closedrange.md) - [ClosedRange.Index](swift/closedrange/index.md) - [CollectionDifference](swift/collectiondifference.md) - [CollectionDifference.Change](swift/collectiondifference/change.md) - [CollectionDifference.Index](swift/collectiondifference/index.md) - [CollectionOfOne](swift/collectionofone.md) - [CollectionOfOne.Iterator](swift/collectionofone/iterator.md) - [ContiguousArray](swift/contiguousarray.md) - [ContinuousClock](swift/continuousclock.md) - [ContinuousClock.Instant](swift/continuousclock/instant.md) - [DecodingError](swift/decodingerror.md) - [DefaultIndices](swift/defaultindices.md) - [DefaultStringInterpolation](swift/defaultstringinterpolation.md) - [Dictionary](swift/dictionary.md) - [Dictionary.Index](swift/dictionary/index.md) - [Dictionary.Iterator](swift/dictionary/iterator.md) - [Dictionary.Keys](swift/dictionary/keys-swift.struct.md) - [Dictionary.Values](swift/dictionary/values-swift.struct.md) - [DiscontiguousSlice](swift/discontiguousslice.md) - [DiscontiguousSlice.Index](swift/discontiguousslice/index.md) - [Double](swift/double.md) - [DropFirstSequence](swift/dropfirstsequence.md) - [DropWhileSequence](swift/dropwhilesequence.md) - [DropWhileSequence.Iterator](swift/dropwhilesequence/iterator.md) - [Duration](swift/duration.md) - [Duration.TimeFormatStyle](swift/duration/timeformatstyle.md) - [Duration.TimeFormatStyle.Attributed](swift/duration/timeformatstyle/attributed-swift.struct.md) - [Duration.UnitsFormatStyle](swift/duration/unitsformatstyle.md) - [Duration.UnitsFormatStyle.Attributed](swift/duration/unitsformatstyle/attributed-swift.struct.md) - [EmptyCollection](swift/emptycollection.md) - [EmptyCollection.Iterator](swift/emptycollection/iterator.md) - [EncodingError](swift/encodingerror.md) - [EnumeratedSequence](swift/enumeratedsequence.md) - [EnumeratedSequence.Iterator](swift/enumeratedsequence/iterator.md) - [ExecuteDistributedTargetError.ErrorCode](distributed/executedistributedtargeterror/errorcode-swift.enum.md) - [FlattenSequence](swift/flattensequence.md) - [FlattenSequence.Index](swift/flattensequence/index.md) - [FlattenSequence.Iterator](swift/flattensequence/iterator.md) - [Float](swift/float.md) - [Float16](swift/float16.md) - [Float80](swift/float80.md) - [FloatingPointClassification](swift/floatingpointclassification.md) - [FloatingPointRoundingRule](swift/floatingpointroundingrule.md) - [FloatingPointSign](swift/floatingpointsign.md) - [IndexingIterator](swift/indexingiterator.md) - [Int](swift/int.md) - [Int128](swift/int128.md) - [Int16](swift/int16.md) - [Int32](swift/int32.md) - [Int64](swift/int64.md) - [Int8](swift/int8.md) - [IteratorSequence](swift/iteratorsequence.md) - [JoinedSequence](swift/joinedsequence.md) - [JoinedSequence.Iterator](swift/joinedsequence/iterator.md) - [KeyValuePairs](swift/keyvaluepairs.md) - [LazyDropWhileSequence](swift/lazydropwhilesequence.md) - [LazyDropWhileSequence.Iterator](swift/lazydropwhilesequence/iterator.md) - [LazyFilterSequence](swift/lazyfiltersequence.md) - [LazyFilterSequence.Iterator](swift/lazyfiltersequence/iterator.md) - [LazyMapSequence](swift/lazymapsequence.md) - [LazyMapSequence.Iterator](swift/lazymapsequence/iterator.md) - [LazyPrefixWhileSequence](swift/lazyprefixwhilesequence.md) - [LazyPrefixWhileSequence.Index](swift/lazyprefixwhilesequence/index.md) - [LazyPrefixWhileSequence.Iterator](swift/lazyprefixwhilesequence/iterator.md) - [LazySequence](swift/lazysequence.md) - [Local](regexbuilder/local.md) - [Lookahead](regexbuilder/lookahead.md) - [Mirror](swift/mirror.md) - [Mirror.DisplayStyle](swift/mirror/displaystyle-swift.enum.md) - [NegativeLookahead](regexbuilder/negativelookahead.md) - [Never](swift/never.md) - [ObjectIdentifier](swift/objectidentifier.md) - [ObservationRegistrar](observation/observationregistrar.md) - [ObservationTracking.Options](observation/observationtracking/options.md) - [OneOrMore](regexbuilder/oneormore.md) - [OpaquePointer](swift/opaquepointer.md) - [Optional](swift/optional.md) - [Optionally](regexbuilder/optionally.md) - [PartialRangeFrom](swift/partialrangefrom.md) - [PartialRangeThrough](swift/partialrangethrough.md) - [PartialRangeUpTo](swift/partialrangeupto.md) - [PrefixSequence](swift/prefixsequence.md) - [PrefixSequence.Iterator](swift/prefixsequence/iterator.md) - [Range](swift/range.md) - [RangeSet](swift/rangeset.md) - [RangeSet.Ranges](swift/rangeset/ranges-swift.struct.md) - [Repeat](regexbuilder/repeat.md) - [Repeated](swift/repeated.md) - [Result](swift/result.md) - [ReversedCollection](swift/reversedcollection.md) - [ReversedCollection.Index](swift/reversedcollection/index.md) - [ReversedCollection.Iterator](swift/reversedcollection/iterator.md) - [SIMD16](swift/simd16.md) - [SIMD2](swift/simd2.md) - [SIMD3](swift/simd3.md) - [SIMD32](swift/simd32.md) - [SIMD4](swift/simd4.md) - [SIMD64](swift/simd64.md) - [SIMD8](swift/simd8.md) - [Set](swift/set.md) - [Set.Index](swift/set/index.md) - [Set.Iterator](swift/set/iterator.md) - [Slice](swift/slice.md) - [StaticBigInt](swift/staticbigint.md) - [StaticString](swift/staticstring.md) - [StrideThrough](swift/stridethrough.md) - [StrideThroughIterator](swift/stridethroughiterator.md) - [StrideTo](swift/strideto.md) - [StrideToIterator](swift/stridetoiterator.md) - [String](swift/string.md) - [String.Encoding](swift/string/encoding.md) - [String.Index](swift/string/index.md) - [String.IntentInputOptions.CapitalizationType](swift/string/intentinputoptions/capitalizationtype-swift.enum.md) - [String.IntentInputOptions.KeyboardType](swift/string/intentinputoptions/keyboardtype-swift.enum.md) - [String.LocalizationValue](swift/string/localizationvalue.md) - [String.UTF16View](swift/string/utf16view.md) - [String.UTF8View](swift/string/utf8view.md) - [String.UnicodeScalarView](swift/string/unicodescalarview.md) - [Substring](swift/substring.md) - [Substring.UTF16View](swift/substring/utf16view.md) - [Substring.UTF8View](swift/substring/utf8view.md) - [Substring.UnicodeScalarView](swift/substring/unicodescalarview.md) - [SuspendingClock](swift/suspendingclock.md) - [SuspendingClock.Instant](swift/suspendingclock/instant.md) - [Task](swift/task.md) - [TaskGroup](swift/taskgroup.md) - [TaskPriority](swift/taskpriority.md) - [ThrowingTaskGroup](swift/throwingtaskgroup.md) - [TryCapture](regexbuilder/trycapture.md) - [UInt](swift/uint.md) - [UInt128](swift/uint128.md) - [UInt128.Words](swift/uint128/words-swift.struct.md) - [UInt16](swift/uint16.md) - [UInt32](swift/uint32.md) - [UInt64](swift/uint64.md) - [UInt8](swift/uint8.md) - [Unicode.ASCII](swift/unicode/ascii.md) - [Unicode.ASCII.Parser](swift/unicode/ascii/parser.md) - [Unicode.GeneralCategory](swift/unicode/generalcategory.md) - [Unicode.NumericType](swift/unicode/numerictype.md) - [Unicode.Scalar](swift/unicode/scalar.md) - [Unicode.Scalar.UTF16View](swift/unicode/scalar/utf16view.md) - [Unicode.Scalar.UTF8View](swift/unicode/scalar/utf8view.md) - [Unicode.UTF16](swift/unicode/utf16.md) - [Unicode.UTF16.ForwardParser](swift/unicode/utf16/forwardparser.md) - [Unicode.UTF16.ReverseParser](swift/unicode/utf16/reverseparser.md) - [Unicode.UTF32](swift/unicode/utf32.md) - [Unicode.UTF32.Parser](swift/unicode/utf32/parser.md) - [Unicode.UTF8](swift/unicode/utf8.md) - [Unicode.UTF8.ForwardParser](swift/unicode/utf8/forwardparser.md) - [Unicode.UTF8.ReverseParser](swift/unicode/utf8/reverseparser.md) - [Unicode.UTF8.ValidationError](swift/unicode/utf8/validationerror.md) - [Unicode.UTF8.ValidationError.Kind](swift/unicode/utf8/validationerror/kind-swift.struct.md) - [Unmanaged](swift/unmanaged.md) - [UnownedJob](swift/unownedjob.md) - [UnownedTaskExecutor](swift/unownedtaskexecutor.md) - [UnsafeBufferPointer](swift/unsafebufferpointer.md) - [UnsafeBufferPointer.Iterator](swift/unsafebufferpointer/iterator.md) - [UnsafeCurrentTask](swift/unsafecurrenttask.md) - [UnsafeMutableBufferPointer](swift/unsafemutablebufferpointer.md) - [UnsafeMutablePointer](swift/unsafemutablepointer.md) - [UnsafeMutableRawBufferPointer](swift/unsafemutablerawbufferpointer.md) - [UnsafeMutableRawPointer](swift/unsafemutablerawpointer.md) - [UnsafePointer](swift/unsafepointer.md) - [UnsafeRawBufferPointer](swift/unsaferawbufferpointer.md) - [UnsafeRawBufferPointer.Iterator](swift/unsaferawbufferpointer/iterator.md) - [UnsafeRawPointer](swift/unsaferawpointer.md) - [WordPair](synchronization/wordpair.md) - [ZeroOrMore](regexbuilder/zeroormore.md) - [Zip2Sequence](swift/zip2sequence.md) - [Zip2Sequence.Iterator](swift/zip2sequence/iterator.md) ## See Also ### Copying - [Copyable](swift/copyable.md) - [BitwiseCopyable](swift/bitwisecopyable.md)