1/*
2 * Copyright (C) 2019 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/PtrTag.h>
29
30namespace WTF {
31
32template<typename PtrType>
33class TaggedArrayStoragePtr {
34public:
35 TaggedArrayStoragePtr()
36 : m_ptr(tagArrayPtr<PtrType>(nullptr, 0))
37 { }
38
39 TaggedArrayStoragePtr(PtrType* ptr, unsigned length)
40 : m_ptr(tagArrayPtr(ptr, length))
41 { }
42
43 PtrType* get(unsigned length) const { return untagArrayPtr(m_ptr, length); }
44 PtrType* getUnsafe() const { return removeArrayPtrTag(m_ptr); }
45
46 void resize(unsigned oldLength, unsigned newLength)
47 {
48 m_ptr = retagArrayPtr(m_ptr, oldLength, newLength);
49 }
50
51 explicit operator bool() const { return !!getUnsafe(); }
52
53private:
54 PtrType* m_ptr;
55};
56
57}
58
59using WTF::TaggedArrayStoragePtr;
60