1 /*
2  * Copyright (c) 2015, Intel Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without modification,
6  * are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice, this
9  * list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright notice,
12  * this list of conditions and the following disclaimer in the documentation and/or
13  * other materials provided with the distribution.
14  *
15  * 3. Neither the name of the copyright holder nor the names of its contributors
16  * may be used to endorse or promote products derived from this software without
17  * specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
26  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <algorithm>
32 #include <type_traits>
33 #include "Iterator.hpp"
34 #include <cassert>
35 
36 namespace utility
37 {
38 
39 /**
40  * Raw copy of one variable to another of the same size
41  *
42  * This can be regarder as a reinterpret_cast but does a copy and does not
43  * break strict-aliasing rules.
44  *
45  * The source and the destination must have the same storage size (e.g. copying
46  * a uint8_t into a uint32_t won't compile)
47  *
48  * @tparam Source The source type
49  * @tparam Destination the destination type (even if it is a reference, this
50  *         function returns by copy)
51  * @param source Source variable
52  * @returns the source, reinterpreted as the destination type
53  */
54 template <class Destination, class Source>
binaryCopy(const Source source)55 typename std::remove_reference<Destination>::type binaryCopy(const Source source)
56 {
57     static_assert(sizeof(Source) == sizeof(Destination),
58                   "Source and Destination must have the same size");
59 
60     using Destination_ = decltype(binaryCopy<Destination>(source));
61 
62     union
63     {
64         Source source;
65         Destination_ destination;
66     } hack;
67 
68     hack.source = source;
69     return hack.destination;
70 }
71 
72 } // namespace utility
73