1// Copyright 2010 The Kyua Authors.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8// * Redistributions of source code must retain the above copyright
9//   notice, this list of conditions and the following disclaimer.
10// * Redistributions in binary form must reproduce the above copyright
11//   notice, this list of conditions and the following disclaimer in the
12//   documentation and/or other materials provided with the distribution.
13// * Neither the name of Google Inc. nor the names of its contributors
14//   may be used to endorse or promote products derived from this software
15//   without specific prior written permission.
16//
17// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29/// \file utils/noncopyable.hpp
30/// Provides the utils::noncopyable class.
31///
32/// The class is provided as a separate module on its own to minimize
33/// header-inclusion side-effects.
34
35#if !defined(UTILS_NONCOPYABLE_HPP)
36#define UTILS_NONCOPYABLE_HPP
37
38
39namespace utils {
40
41
42/// Forbids copying a class at compile-time.
43///
44/// Inheriting from this class delivers a private copy constructor and an
45/// assignment operator that effectively forbid copying the class during
46/// compilation.
47///
48/// Always use private inheritance.
49class noncopyable {
50    /// Data placeholder.
51    ///
52    /// The class cannot be empty; otherwise we get ABI-stability warnings
53    /// during the build, which will break it due to strict checking.
54    int _noncopyable_dummy;
55
56    /// Private copy constructor to deny copying of subclasses.
57    noncopyable(const noncopyable&);
58
59    /// Private assignment constructor to deny copying of subclasses.
60    ///
61    /// \return A reference to the object.
62    noncopyable& operator=(const noncopyable&);
63
64protected:
65    // Explicitly needed to provide some non-private functions.  Otherwise
66    // we also get some warnings during the build.
67    noncopyable(void) {}
68    ~noncopyable(void) {}
69};
70
71
72}  // namespace utils
73
74
75#endif  // !defined(UTILS_NONCOPYABLE_HPP)
76