Files
swift-mirror/stdlib/core/ArrayBody.swift
Jordan Rose cca27d02a0 Tag everything in the standard library with accessibility attributes.
Keep calm: remember that the standard library has many more public exports
than the average target, and that this contains ALL of them at once.
I also deliberately tried to tag nearly every top-level decl, even if that
was just to explicitly mark things @internal, to make sure I didn't miss
something.

This does export more than we might want to, mostly for protocol conformance
reasons, along with our simple-but-limiting typealias rule. I tried to also
mark things private where possible, but it's really going to be up to the
standard library owners to get this right. This is also only validated
against top-level access control; I haven't fully tested against member-level
access control yet, and none of our semantic restrictions are in place.

Along the way I also noticed bits of stdlib cruft; to keep this patch
understandable, I didn't change any of them.

Swift SVN r19145
2014-06-24 21:32:18 +00:00

66 lines
2.2 KiB
Swift

//===--- ArrayBody.swift - Data needed once per array ---------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// Array storage begins with a Body and ends with a sequence of
// contiguous Elements. This struct describes the Body part.
//
//===----------------------------------------------------------------------===//
@internal struct _ArrayBody {
init(count: Int, capacity: Int, elementTypeIsBridgedVerbatim: Bool = false) {
_sanityCheck(count >= 0)
_sanityCheck(capacity >= 0)
self.count = count
self._capacityAndFlags
= (UInt(capacity) << 1) | (elementTypeIsBridgedVerbatim ? 1 : 0)
}
/// In principle CountAndCapacity shouldn't need to be default
/// constructed, but since we want to claim all the allocated
/// capacity after a new buffer is allocated, it's typical to want
/// to update it immediately after construction.
init() {
self.count = 0
self._capacityAndFlags = 0
}
/// The number of elements stored in this Array
var count: Int
/// The number of elements that can be stored in this Array without
/// reallocation.
var capacity: Int {
return Int(_capacityAndFlags >> 1)
}
/// Is the Element type bitwise-compatible with some Objective-C
/// class? The answer is---in principle---statically-knowable, but
/// I don't expect to be able to get this information to the
/// optimizer before 1.0 ships, so we store it in a bit here to
/// avoid the cost of calls into the runtime that compute the
/// answer.
var elementTypeIsBridgedVerbatim: Bool {
get {
return (_capacityAndFlags & 0x1) != 0
}
set {
_capacityAndFlags
= newValue ? _capacityAndFlags | 1 : _capacityAndFlags & ~1
}
}
/// Storage optimization: compresses capacity and
/// elementTypeIsBridgedVerbatim together.
var _capacityAndFlags: UInt
}