Swift の Array やら ArraySlice やらポインタの変換まとめ

Swift の以下の型の間で、直接相互に変換できるものを網羅してみる。

UnsafeRawPointer
UnsafeMutableRawPointer

UnsafePointer< Int >
UnsafeMutablePointer< Int >

UnsafeRawBufferPointer
UnsafeMutableRawBufferPointer

UnsafeBufferPointer< Int >
UnsafeMutableBufferPointer< Int >

Array< Int >
ArraySlice< Int >

OpaquePointer

ポインタ名	変更	型	サイズ
UnsafeRawPointer
UnsafeMutableRawPointer	○
UnsafePointer< Int >		○
UnsafeMutablePointer< Int >	○	○
UnsafeRawBufferPointer			○
UnsafeMutableRawBufferPointer	○		○
UnsafeBufferPointer< Int >		○	○
UnsafeMutableBufferPointer< Int >	○	○	○
let Array< Int >		○	○
var Array< Int >	○	○	○
let ArraySlice< Int >		○	○
var ArraySlice< Int >	○	○	○
OpaquePointer

• 変更できないものからできるものには変換するには、mutating:を使う。
• 型のないものからあるものには変換するには、assumingMemoryBound( to: Int.self )を使う。
• サイズのないものからあるものには変換できない。
• withUnsafeRawBufferPointer という名前のメソッドはない。withUnsafeBytesを使う。
• withUnsafeMutableRawBufferPointer という名前のメソッドはない。withUnsafeMutableBytesを使う。

var Array< Int > から

var w   : Array< Int >                      = [ 1, 2, 3 ]

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w )
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: w )

let _   : UnsafePointer< Int >              = UnsafePointer( w )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: w )

let _   : UnsafeRawBufferPointer            = w.withUnsafeBytes { $0 }
let _   : UnsafeMutableRawBufferPointer     = w.withUnsafeMutableBytes { $0 }

let _   : UnsafeBufferPointer< Int >        = w.withUnsafeBufferPointer { $0 }
let _   : UnsafeMutableBufferPointer< Int > = w.withUnsafeMutableBufferPointer { $0 }

let _   : ArraySlice< Int >                 = ArraySlice( w )

let _   : OpaquePointer                     = OpaquePointer( w )

let Array< Int > から

let w   : Array< Int >                      = [ 1, 2, 3 ]

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w )
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: w )

let _   : UnsafePointer< Int >              = UnsafePointer( w )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: w )

let _   : UnsafeRawBufferPointer            = w.withUnsafeBytes { $0 }
let _   : UnsafeMutableRawBufferPointer     = UnsafeMutableRawBufferPointer( mutating: w.withUnsafeBytes { $0 } )

let _   : UnsafeBufferPointer< Int >        = w.withUnsafeBufferPointer { $0 }
let _   : UnsafeMutableBufferPointer< Int > = UnsafeMutableBufferPointer( mutating: w.withUnsafeBufferPointer { $0 } )

let _   : ArraySlice< Int >                 = ArraySlice( w )

let _   : OpaquePointer                     = OpaquePointer( w )

var ArraySlice< Int > から

var w   : ArraySlice< Int >                 = ArraySlice( [ 1, 2, 3 ] )

let _   : UnsafeRawPointer                  = w.withUnsafeBytes { $0.baseAddress! }
let _   : UnsafeMutableRawPointer           = w.withUnsafeMutableBytes { $0.baseAddress! }

let _   : UnsafePointer< Int >              = w.withUnsafeBufferPointer { $0.baseAddress! }
let _   : UnsafeMutablePointer< Int >       = w.withUnsafeMutableBufferPointer { $0.baseAddress! }

let _   : UnsafeRawBufferPointer            = w.withUnsafeBytes { $0 }
let _   : UnsafeMutableRawBufferPointer     = w.withUnsafeMutableBytes { $0 }

let _   : UnsafeBufferPointer< Int >        = w.withUnsafeBufferPointer { $0 }
let _   : UnsafeMutableBufferPointer< Int > = w.withUnsafeMutableBufferPointer { $0 }

let _   : Array< Int >                      = Array( w )

let _   : OpaquePointer                     = OpaquePointer( w.withUnsafeBufferPointer { $0.baseAddress! } )

let ArraySlice< Int > から

let w   : ArraySlice< Int >                 = ArraySlice( [ 1, 2, 3 ] )

let _   : UnsafeRawPointer                  = w.withUnsafeBytes { $0.baseAddress! }
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: w.withUnsafeBytes { $0.baseAddress! } )

let _   : UnsafePointer< Int >              = w.withUnsafeBufferPointer { $0.baseAddress! }
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: w.withUnsafeBufferPointer { $0.baseAddress! } )

let _   : UnsafeRawBufferPointer            = w.withUnsafeBytes { $0 }
let _   : UnsafeMutableRawBufferPointer     = UnsafeMutableRawBufferPointer( mutating: w.withUnsafeBytes { $0 } )

let _   : UnsafeBufferPointer< Int >        = w.withUnsafeBufferPointer { $0 }
let _   : UnsafeMutableBufferPointer< Int > = UnsafeMutableBufferPointer( mutating: w.withUnsafeBufferPointer { $0 } )

let _   : Array< Int >                      = Array( w )

let _   : OpaquePointer                     = OpaquePointer( w.withUnsafeBufferPointer { $0.baseAddress! } )

UnsafeRawPointer から

let w   : UnsafeRawPointer                  = UnsafeRawPointer( [ 1, 2, 3 ] )

let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: w )

let _   : UnsafePointer< Int >              = w.assumingMemoryBound( to: Int.self )
Int.self )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: w.assumingMemoryBound( to: Int.self ) )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutableRawPointer( mutating: w ).assumingMemoryBound( to:  Int.self ) )   // こんなのも可能

let _   : OpaquePointer                     = OpaquePointer( w )

UnsafeMutableRawPointer から

let w   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: [ 1, 2, 3 ] )

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w )

let _   : UnsafePointer< Int >              = UnsafePointer( w.assumingMemoryBound( to: Int.self ) )
let _   : UnsafeMutablePointer< Int >       = w.assumingMemoryBound( to: Int.self )

let _   : OpaquePointer                     = OpaquePointer( w )

UnsafePointer< Int > から

let w   : UnsafePointer< Int >              = UnsafePointer( [ 1, 2, 3 ] )

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w )
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: w )

let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: w )

let _   : OpaquePointer                     = OpaquePointer( w )

UnsafeMutablePointer< Int > から

let w   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: [ 1, 2, 3 ] )

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w )
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( w )

let _   : UnsafePointer< Int >              = UnsafePointer( w )

let _   : OpaquePointer                     = OpaquePointer( w )

UnsafeRawBufferPointer から

let w   : UnsafeRawBufferPointer            = [ 1, 2, 3 ].withUnsafeBytes { $0 }

let _   : UnsafeRawPointer                  = w.baseAddress!
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: w.baseAddress! )

let _   : UnsafePointer< Int >              = w.baseAddress!.assumingMemoryBound( to: Int.self )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: w.baseAddress!.assumingMemoryBound( to: Int.self ) )

let _   : UnsafeMutableRawBufferPointer     = UnsafeMutableRawBufferPointer( mutating: w )

let _   : OpaquePointer                     = OpaquePointer( w.baseAddress! )

UnsafeMutableRawBufferPointer から

var wArray = [ 1, 2, 3 ]
let w   : UnsafeMutableRawBufferPointer     = wArray.withUnsafeMutableBytes { $0 }

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w.baseAddress! )
let _   : UnsafeMutableRawPointer           = w.baseAddress!

let _   : UnsafePointer< Int >              = UnsafePointer( w.baseAddress!.assumingMemoryBound( to: Int.self ) )
let _   : UnsafeMutablePointer< Int >       = w.baseAddress!.assumingMemoryBound( to: Int.self )

let _   : UnsafeRawBufferPointer            = UnsafeRawBufferPointer( w )

let _   : OpaquePointer                     = OpaquePointer( w.baseAddress! )

UnsafeBufferPointer< Int > から

let w   : UnsafeBufferPointer               = [ 1, 2, 3 ].withUnsafeBufferPointer { $0 }

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w.baseAddress! )
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( mutating: w.baseAddress! )

let _   : UnsafePointer< Int >              = UnsafePointer( w.baseAddress! )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( mutating: w.baseAddress! )

let _   : UnsafeRawBufferPointer            = UnsafeRawBufferPointer( w )
let _   : UnsafeMutableRawBufferPointer     = UnsafeMutableRawBufferPointer( mutating: UnsafeRawBufferPointer( w ) )

let _   : UnsafeMutableBufferPointer< Int > = UnsafeMutableBufferPointer( mutating: w )

let _   : Array< Int >                      = Array( w )
let _   : ArraySlice< Int >                 = ArraySlice( w )

let _   : OpaquePointer                     = OpaquePointer( w.baseAddress! )

UnsafeMutableBufferPointer< Int > から

var wArray = [ 1, 2, 3 ]
let w   : UnsafeMutableBufferPointer        = wArray.withUnsafeMutableBufferPointer { $0 }

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w.baseAddress! )
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( w.baseAddress! )

let _   : UnsafePointer< Int >              = UnsafePointer( w.baseAddress! )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( w.baseAddress! )

let _   : UnsafeRawBufferPointer            = UnsafeRawBufferPointer( w )
let _   : UnsafeMutableRawBufferPointer     = UnsafeMutableRawBufferPointer( w )

let _   : UnsafeBufferPointer< Int >        = UnsafeBufferPointer( w )

let _   : Array< Int >                      = Array( w )
let _   : ArraySlice< Int >                 = ArraySlice( w )

let _   : OpaquePointer                     = OpaquePointer( w.baseAddress! )

OpaquePointer から

let w   : OpaquePointer                     = OpaquePointer( [ 1, 2, 3 ] )

let _   : UnsafeRawPointer                  = UnsafeRawPointer( w )
let _   : UnsafeMutableRawPointer           = UnsafeMutableRawPointer( w )

let _   : UnsafePointer< Int >              = UnsafePointer( w )
let _   : UnsafeMutablePointer< Int >       = UnsafeMutablePointer( w )