1 // Copyright 2010 Google Inc. 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 39 namespace 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. 49 class 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 noncopyable& operator=(const noncopyable&); 61 62 protected: 63 // Explicitly needed to provide some non-private functions. Otherwise 64 // we also get some warnings during the build. noncopyable(void)65 noncopyable(void) {} ~noncopyable(void)66 ~noncopyable(void) {} 67 }; 68 69 70 } // namespace utils 71 72 73 #endif // !defined(UTILS_NONCOPYABLE_HPP) 74