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 * 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 */
AsConst(Type & aObject)50 template <typename Type> const Type &AsConst(Type &aObject) { return const_cast<const Type &>(aObject); }
51
52 /**
53 * Casts a given non-const pointer to a const pointer.
54 *
55 * @tparam Type The pointer type.
56 *
57 * @param[in] aPointer A non-const pointer to an object.
58 *
59 * @returns A const pointer to @p aPointer pointer.
60 */
AsConst(Type * aPointer)61 template <typename Type> const Type *AsConst(Type *aPointer) { return const_cast<const Type *>(aPointer); }
62
63 /**
64 * Casts a given const reference to a non-const reference.
65 *
66 * @tparam Type The reference type.
67 *
68 * @param[in] aObject A const reference to an object.
69 *
70 * @returns A non-const reference to @p aObject reference.
71 */
AsNonConst(const Type & aObject)72 template <typename Type> Type &AsNonConst(const Type &aObject) { return const_cast<Type &>(aObject); }
73
74 /**
75 * Casts a given const pointer to a non-const pointer.
76 *
77 * @tparam Type The pointer type.
78 *
79 * @param[in] aPointer A const pointer to an object.
80 *
81 * @returns A non-const pointer to @p aPointer pointer.
82 */
AsNonConst(const Type * aPointer)83 template <typename Type> Type *AsNonConst(const Type *aPointer) { return const_cast<Type *>(aPointer); }
84
85 } // namespace ot
86
87 #endif // CONST_CAST_HPP_
88