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//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
// NOTE: The below is necessary for fast String initialization from untyped
// memory. When we add Collection.withContiguousRawStorageIfAvailable(), we can
// deprecate this functionality.
@usableFromInline
internal protocol _HasContiguousBytes {
func withUnsafeBytes<R>(
_ body: (UnsafeRawBufferPointer) throws -> R
) rethrows -> R
var _providesContiguousBytesNoCopy: Bool { get }
}
extension _HasContiguousBytes {
@inlinable
var _providesContiguousBytesNoCopy: Bool {
@inline(__always) get { return true }
}
}
extension Array: _HasContiguousBytes {
@inlinable
var _providesContiguousBytesNoCopy: Bool {
@inline(__always) get {
#if _runtime(_ObjC)
return _buffer._isNative
#else
return true
#endif
}
}
}
extension ContiguousArray: _HasContiguousBytes {}
extension UnsafeBufferPointer: _HasContiguousBytes {
@inlinable @inline(__always)
func withUnsafeBytes<R>(
_ body: (UnsafeRawBufferPointer) throws -> R
) rethrows -> R {
let ptr = UnsafeRawPointer(self.baseAddress)
let len = self.count &* MemoryLayout<Element>.stride
return try body(UnsafeRawBufferPointer(start: ptr, count: len))
}
}
extension UnsafeMutableBufferPointer: _HasContiguousBytes {
@inlinable @inline(__always)
func withUnsafeBytes<R>(
_ body: (UnsafeRawBufferPointer) throws -> R
) rethrows -> R {
let ptr = UnsafeRawPointer(self.baseAddress)
let len = self.count &* MemoryLayout<Element>.stride
return try body(UnsafeRawBufferPointer(start: ptr, count: len))
}
}
extension UnsafeRawBufferPointer: _HasContiguousBytes {
@inlinable @inline(__always)
func withUnsafeBytes<R>(
_ body: (UnsafeRawBufferPointer) throws -> R
) rethrows -> R {
return try body(self)
}
}
extension UnsafeMutableRawBufferPointer: _HasContiguousBytes {
@inlinable @inline(__always)
func withUnsafeBytes<R>(
_ body: (UnsafeRawBufferPointer) throws -> R
) rethrows -> R {
return try body(UnsafeRawBufferPointer(self))
}
}
extension String: _HasContiguousBytes {
@inlinable
internal var _providesContiguousBytesNoCopy: Bool {
@inline(__always) get { return self._guts.isFastUTF8 }
}
@inlinable @inline(__always)
internal func withUnsafeBytes<R>(
_ body: (UnsafeRawBufferPointer) throws -> R
) rethrows -> R {
var copy = self
return try copy.withUTF8 { return try body(UnsafeRawBufferPointer($0)) }
}
}
extension Substring: _HasContiguousBytes {
@inlinable
internal var _providesContiguousBytesNoCopy: Bool {
@inline(__always) get { return self._wholeGuts.isFastUTF8 }
}
@inlinable @inline(__always)
internal func withUnsafeBytes<R>(
_ body: (UnsafeRawBufferPointer) throws -> R
) rethrows -> R {
var copy = self
return try copy.withUTF8 { return try body(UnsafeRawBufferPointer($0)) }
}
}
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