# AnyColumn A type-erased column. ``` struct AnyColumn ``` ## Overview `AnyColumn` is a column type that conceals the type of its elements, unlike [`Column`](/documentation/TabularData/Column), its typed counterpart. ## Topics ### Inspecting a Type-Erased Column [`var name: String`](/documentation/TabularData/AnyColumn/name) The name of the column. [`var count: Int`](/documentation/TabularData/AnyColumn/count) The number of elements in the column. [`var missingCount: Int`](/documentation/TabularData/AnyColumn/missingCount) The number of missing elements in the column. [`var wrappedElementType: any Any.Type`](/documentation/TabularData/AnyColumn/wrappedElementType) The underlying type of the column’s elements. [`func isNil(at: Int) -> Bool`](/documentation/TabularData/AnyColumn/isNil(at:)) Returns a Boolean that indicates whether the element at the index is missing. ### Creating a Column of the Same Type [`var prototype: any AnyColumnPrototype`](/documentation/TabularData/AnyColumn/prototype) A prototype that creates type-erased columns with the same underlying type as the column slice. ### Creating a Typed Column [`func assumingType(T.Type) -> Column`](/documentation/TabularData/AnyColumn/assumingType(_:)) Returns the underlying typed column. ### Adding Elements [`func append(Any?)`](/documentation/TabularData/AnyColumn/append(_:)) Appends an optional element to the column. [`func append(contentsOf: AnyColumn)`](/documentation/TabularData/AnyColumn/append(contentsOf:)-2in58) Appends the contents of another column to the column. [`func append(contentsOf: AnyColumnSlice)`](/documentation/TabularData/AnyColumn/append(contentsOf:)-az5b) Appends the contents of a column slice to the column. ### Removing an Element [`func remove(at: Int)`](/documentation/TabularData/AnyColumn/remove(at:)) Removes an element from the column. ### Accessing Elements [`subscript(Int) -> Any?`](/documentation/TabularData/AnyColumn/subscript(_:)-6z1b5) Accesses an element at an index. [`subscript(Range) -> AnyColumnSlice`](/documentation/TabularData/AnyColumn/subscript(_:)-1n9t9) Accesses a contiguous subrange of the elements. ### Creating a Slice of Unique Elements [`func distinct() -> AnyColumnSlice`](/documentation/TabularData/AnyColumn/distinct()) Generates a column slice that contains unique elements. ### Creating a Slice by Masking Elements [`subscript(C) -> AnyColumnSlice`](/documentation/TabularData/AnyColumn/subscript(_:)-3658g) Returns a slice of the column by selecting elements with a collection of Booleans. ### Encoding a Column [`func encode(T.Type, using: Encoder) throws`](/documentation/TabularData/AnyColumn/encode(_:using:)) Encodes each element of the column. [`func encoded(T.Type, using: Encoder) throws -> AnyColumn`](/documentation/TabularData/AnyColumn/encoded(_:using:)) Generates a column by encoding each element’s value. ### Decoding a Column [`func decode(T.Type, using: Decoder) throws`](/documentation/TabularData/AnyColumn/decode(_:using:)) Decodes the data in each element of the column. [`func decoded(T.Type, using: Decoder) throws -> AnyColumn`](/documentation/TabularData/AnyColumn/decoded(_:using:)) Decodes data for each element of the column. ### Describing a Column [`var description: String`](/documentation/TabularData/AnyColumn/description) A text representation of the column. [`var debugDescription: String`](/documentation/TabularData/AnyColumn/debugDescription) A text representation of the column suitable for debugging. [`var customMirror: Mirror`](/documentation/TabularData/AnyColumn/customMirror) A mirror that reflects the column. ### Comparing Two Columns [`static func == (AnyColumn, AnyColumn) -> Bool`](/documentation/TabularData/AnyColumn/==(_:_:)) Returns a Boolean that indicates whether the columns are equal. ### Hashing a Column [`func hash(into: inout Hasher)`](/documentation/TabularData/AnyColumn/hash(into:)) Hashes the essential components of the column by feeding them into a hasher. ### Supporting Types ### Invoking Protocol Methods ### Default Implementations [CustomDebugStringConvertible Implementations](/documentation/TabularData/AnyColumn/CustomDebugStringConvertible-Implementations) [CustomReflectable Implementations](/documentation/TabularData/AnyColumn/CustomReflectable-Implementations) [CustomStringConvertible Implementations](/documentation/TabularData/AnyColumn/CustomStringConvertible-Implementations) [Equatable Implementations](/documentation/TabularData/AnyColumn/Equatable-Implementations) [Hashable Implementations](/documentation/TabularData/AnyColumn/Hashable-Implementations) [RandomAccessCollection Implementations](/documentation/TabularData/AnyColumn/RandomAccessCollection-Implementations) ## Relationships ### Conforms To [`BidirectionalCollection`](/documentation/Swift/BidirectionalCollection) [`Hashable`](/documentation/Swift/Hashable) [`Equatable`](/documentation/Swift/Equatable) [`Escapable`](/documentation/Swift/Escapable) [`MutableCollection`](/documentation/Swift/MutableCollection) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) [`RandomAccessCollection`](/documentation/Swift/RandomAccessCollection) [`Collection`](/documentation/Swift/Collection) [`Sequence`](/documentation/Swift/Sequence) [`CustomReflectable`](/documentation/Swift/CustomReflectable) [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`Copyable`](/documentation/Swift/Copyable) [`AnyColumnProtocol`](/documentation/TabularData/AnyColumnProtocol) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)