1 /*
2 * Copyright (c) 2021, The OpenThread Authors.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions 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 * 3. Neither the name of the copyright holder nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 /**
30 * @file
31 * This file includes helper methods to cast between const and non-const objects and/or pointers.
32 */
33
34 #ifndef CONST_CAST_HPP_
35 #define CONST_CAST_HPP_
36
37 #include "openthread-core-config.h"
38
39 namespace ot {
40
41 /**
42 * This template method casts a given non-const reference to a const reference.
43 *
44 * @tparam Type The reference type.
45 *
46 * @param[in] aObject A non-const reference to an object.
47 *
48 * @returns A const reference to @p aObject reference.
49 *
50 */
AsConst(Type & aObject)51 template <typename Type> const Type &AsConst(Type &aObject)
52 {
53 return const_cast<const Type &>(aObject);
54 }
55
56 /**
57 * This template method casts a given non-const pointer to a const pointer.
58 *
59 * @tparam Type The pointer type.
60 *
61 * @param[in] aPointer A non-const pointer to an object.
62 *
63 * @returns A const pointer to @p aPointer pointer.
64 *
65 */
AsConst(Type * aPointer)66 template <typename Type> const Type *AsConst(Type *aPointer)
67 {
68 return const_cast<const Type *>(aPointer);
69 }
70
71 /**
72 * This template method casts a given const reference to a non-const reference.
73 *
74 * @tparam Type The reference type.
75 *
76 * @param[in] aObject A const reference to an object.
77 *
78 * @returns A non-const reference to @p aObject reference.
79 *
80 */
AsNonConst(const Type & aObject)81 template <typename Type> Type &AsNonConst(const Type &aObject)
82 {
83 return const_cast<Type &>(aObject);
84 }
85
86 /**
87 * This template method casts a given const pointer to a non-const pointer.
88 *
89 * @tparam Type The pointer type.
90 *
91 * @param[in] aPointer A const pointer to an object.
92 *
93 * @returns A non-const pointer to @p aPointer pointer.
94 *
95 */
AsNonConst(const Type * aPointer)96 template <typename Type> Type *AsNonConst(const Type *aPointer)
97 {
98 return const_cast<Type *>(aPointer);
99 }
100
101 } // namespace ot
102
103 #endif // CONST_CAST_HPP_
104