1/*
2 * Copyright (c) 2017, Intel Corporation
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * * Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 * * 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 * * Neither the name of Intel Corporation nor the names of its contributors
13 * may be used to endorse or promote products derived from this software
14 * 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 OWNER 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
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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 * \brief Ordered operators: provides all the other compare operators for types
31 * that provide equal and less-than.
32 *
33 * This is similar to Boost's totally_ordered class, but much simpler and
34 * without injecting the boost namespace into ADL lookup.
35 */
36
37#ifndef UTIL_OPERATORS_H
38#define UTIL_OPERATORS_H
39
40namespace ue2 {
41
42/**
43 * \brief Ordered operators: provides all the other compare operators for types
44 * that provide equal and less-than.
45 *
46 * Simply inherit from this class with your class name as its template
47 * parameter.
48 */
49template<typename T>
50class totally_ordered {
51public:
52 friend bool operator!=(const T &a, const T &b) { return !(a == b); }
53 friend bool operator<=(const T &a, const T &b) { return !(b < a); }
54 friend bool operator>(const T &a, const T &b) { return b < a; }
55 friend bool operator>=(const T &a, const T &b) { return !(a < b); }
56};
57
58} // namespace
59
60#endif // UTIL_OPERATORS_H
61