1 /* 2 * Copyright (c) 2020, 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 definitions for Equatable class for OpenThread objects. 32 */ 33 34 #ifndef EQUATABLE_HPP_ 35 #define EQUATABLE_HPP_ 36 37 #include "openthread-core-config.h" 38 39 #include <string.h> 40 41 namespace ot { 42 43 /** 44 * This template class defines an overload of operator `!=`. 45 * 46 * The `!=` implementation uses an existing `==` overload provided by the `Type` class. 47 * 48 * Users of this class should follow CRTP-style inheritance, i.e., the `Type` class itself should publicly inherit 49 * from `Unequatable<Type>`. 50 * 51 */ 52 template <typename Type> class Unequatable 53 { 54 public: 55 /** 56 * This method overloads operator `!=` to evaluate whether or not two instances of `Type` are equal. 57 * 58 * This is implemented in terms of an existing `==` overload provided by `Type` class itself. 59 * 60 * @param[in] aOther The other `Type` instance to compare with. 61 * 62 * @retval TRUE If the two `Type` instances are not equal. 63 * @retval FALSE If the two `Type` instances are equal. 64 * 65 */ operator !=(const Type & aOther) const66 bool operator!=(const Type &aOther) const { return !(*static_cast<const Type *>(this) == aOther); } 67 }; 68 69 /** 70 * This template class defines overloads of operators `==` and `!=`. 71 * 72 * The `==` implementation simply compares all the bytes of two `Type` instances to be equal (using `memcmp()`). 73 * 74 * Users of this class should follow CRTP-style inheritance, i.e., the `Type` class itself should publicly inherit 75 * from `Equatable<Type>`. 76 * 77 */ 78 template <typename Type> class Equatable : public Unequatable<Type> 79 { 80 public: 81 /** 82 * This method overloads operator `==` to evaluate whether or not two instances of `Type` are equal. 83 * 84 * @param[in] aOther The other `Type` instance to compare with. 85 * 86 * @retval TRUE If the two `Type` instances are equal. 87 * @retval FALSE If the two `Type` instances are not equal. 88 * 89 */ operator ==(const Type & aOther) const90 bool operator==(const Type &aOther) const 91 { 92 return memcmp(static_cast<const Type *>(this), &aOther, sizeof(Type)) == 0; 93 } 94 }; 95 96 } // namespace ot 97 98 #endif // EQUATABLE_HPP_ 99
