# MutableCollection Implementations ## Topics ### Instance Methods [`func moveSubranges(RangeSet, to: Self.Index) -> Range`](/documentation/Swift/UnsafeMutableRawBufferPointer/moveSubranges(_:to:)) Moves the elements in the given subranges to just before the element at the specified index. [`func partition(by: (Self.Element) throws -> Bool) rethrows -> Self.Index`](/documentation/Swift/UnsafeMutableRawBufferPointer/partition(by:)-33su4) Reorders the elements of the collection such that all the elements that match the given predicate are after all the elements that don’t match. [`func partition(by: (Self.Element) throws -> Bool) rethrows -> Self.Index`](/documentation/Swift/UnsafeMutableRawBufferPointer/partition(by:)-90pny) Reorders the elements of the collection such that all the elements that match the given predicate are after all the elements that don’t match. [`func reverse()`](/documentation/Swift/UnsafeMutableRawBufferPointer/reverse()) Reverses the elements of the collection in place. [`func shuffle()`](/documentation/Swift/UnsafeMutableRawBufferPointer/shuffle()) Shuffles the collection in place. [`func shuffle(using: inout T)`](/documentation/Swift/UnsafeMutableRawBufferPointer/shuffle(using:)) Shuffles the collection in place, using the given generator as a source for randomness. [`func sort()`](/documentation/Swift/UnsafeMutableRawBufferPointer/sort()) Sorts the collection in place. [`func sort(by: (Self.Element, Self.Element) throws -> Bool) rethrows`](/documentation/Swift/UnsafeMutableRawBufferPointer/sort(by:)) Sorts the collection in place, using the given predicate as the comparison between elements. [`func swapAt(Int, Int)`](/documentation/Swift/UnsafeMutableRawBufferPointer/swapAt(_:_:)) Exchanges the byte values at the specified indices in this buffer’s memory. [`func withContiguousMutableStorageIfAvailable((inout UnsafeMutableBufferPointer) throws -> R) rethrows -> R?`](/documentation/Swift/UnsafeMutableRawBufferPointer/withContiguousMutableStorageIfAvailable(_:)) Executes a closure on the collection’s contiguous storage. ### Subscripts [`subscript(Range) -> Slice`](/documentation/Swift/UnsafeMutableRawBufferPointer/subscript(_:)-3g42) Accesses a contiguous subrange of the collection’s elements. [`subscript(Range) -> Slice`](/documentation/Swift/UnsafeMutableRawBufferPointer/subscript(_:)-3i1y) Accesses a contiguous subrange of the collection’s elements. [`subscript(R) -> Self.SubSequence`](/documentation/Swift/UnsafeMutableRawBufferPointer/subscript(_:)-3kwnc) [`subscript(UnboundedRange) -> Self.SubSequence`](/documentation/Swift/UnsafeMutableRawBufferPointer/subscript(_:)-3pmfu) [`subscript(Range) -> Self.SubSequence`](/documentation/Swift/UnsafeMutableRawBufferPointer/subscript(_:)-9v9lo) [`subscript(Int) -> UnsafeMutableRawBufferPointer.Element`](/documentation/Swift/UnsafeMutableRawBufferPointer/subscript(_:)-u791) Accesses the byte at the given offset in the memory region as a `UInt8` value. [`subscript(Range) -> UnsafeMutableRawBufferPointer.SubSequence`](/documentation/Swift/UnsafeMutableRawBufferPointer/subscript(_:)-znv7) Accesses the bytes in the specified memory region. --- 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)