mirror of
https://github.com/apple/swift.git
synced 2025-12-21 12:14:44 +01:00
559092bbf2
- Expand pre-example explanations - Update documentation for SE-0118 - Removing remaining 'iff' usage - Revise Array discussion - Fix formIndex(_:offsetBy) parameter formatting - Improve index/formIndex(_:offsetBy:(limitedBy:)?) discussion - Update Quick Look discussions - Fixes grammar inconsistencies - Adds parameter / return documentation - Adds and expands on examples - Revises AnyObject discussion for new `id` bridging rules - Revise readLine, print, and assertion functions - Add missing docs to String index-moving methods
93 lines
3.0 KiB
Swift
93 lines
3.0 KiB
Swift
//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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/// A stdlib-internal protocol modeled by the intrinsic pointer types,
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/// UnsafeMutablePointer, UnsafePointer, and
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/// AutoreleasingUnsafeMutablePointer.
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public protocol _Pointer {
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/// The underlying raw pointer value.
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var _rawValue: Builtin.RawPointer { get }
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/// Creates a pointer from a raw value.
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init(_ _rawValue: Builtin.RawPointer)
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}
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/// Derive a pointer argument from a convertible pointer type.
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@_transparent
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public // COMPILER_INTRINSIC
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func _convertPointerToPointerArgument<
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FromPointer : _Pointer,
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ToPointer : _Pointer
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>(_ from: FromPointer) -> ToPointer {
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return ToPointer(from._rawValue)
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}
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/// Derive a pointer argument from the address of an inout parameter.
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@_transparent
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public // COMPILER_INTRINSIC
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func _convertInOutToPointerArgument<
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ToPointer : _Pointer
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>(_ from: Builtin.RawPointer) -> ToPointer {
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return ToPointer(from)
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}
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/// Derive a pointer argument from a value array parameter.
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///
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/// This always produces a non-null pointer, even if the array doesn't have any
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/// storage.
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@_transparent
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public // COMPILER_INTRINSIC
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func _convertConstArrayToPointerArgument<
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FromElement,
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ToPointer: _Pointer
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>(_ arr: [FromElement]) -> (AnyObject?, ToPointer) {
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let (owner, opaquePointer) = arr._cPointerArgs()
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let validPointer: ToPointer
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if let addr = opaquePointer {
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validPointer = ToPointer(addr._rawValue)
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} else {
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let lastAlignedValue = ~(MemoryLayout<FromElement>.alignment - 1)
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let lastAlignedPointer = UnsafeRawPointer(bitPattern: lastAlignedValue)!
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validPointer = ToPointer(lastAlignedPointer._rawValue)
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}
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return (owner, validPointer)
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}
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/// Derive a pointer argument from an inout array parameter.
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///
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/// This always produces a non-null pointer, even if the array's length is 0.
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@_transparent
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public // COMPILER_INTRINSIC
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func _convertMutableArrayToPointerArgument<
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FromElement,
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ToPointer : _Pointer
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>(_ a: inout [FromElement]) -> (AnyObject?, ToPointer) {
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// TODO: Putting a canary at the end of the array in checked builds might
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// be a good idea
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// Call reserve to force contiguous storage.
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a.reserveCapacity(0)
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_debugPrecondition(a._baseAddressIfContiguous != nil || a.isEmpty)
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return _convertConstArrayToPointerArgument(a)
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}
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/// Derive a UTF-8 pointer argument from a value string parameter.
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public // COMPILER_INTRINSIC
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func _convertConstStringToUTF8PointerArgument<
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ToPointer : _Pointer
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>(_ str: String) -> (AnyObject?, ToPointer) {
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let utf8 = Array(str.utf8CString)
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return _convertConstArrayToPointerArgument(utf8)
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}
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