| Brian Silverman | 407d3cd | 2018-08-04 17:48:52 -0700 | [diff] [blame^] | 1 | [/ |
| 2 | Copyright 1999-2003 Beman Dawes |
| 3 | Copyright 2014 Peter Dimov |
| 4 | |
| 5 | Distributed under the Boost Software License, Version 1.0. |
| 6 | |
| 7 | See accompanying file LICENSE_1_0.txt |
| 8 | or copy at http://boost.org/LICENSE_1_0.txt |
| 9 | ] |
| 10 | |
| 11 | [section:noncopyable noncopyable] |
| 12 | |
| 13 | [simplesect Authors] |
| 14 | |
| 15 | * Dave Abrahams |
| 16 | |
| 17 | [endsimplesect] |
| 18 | |
| 19 | [section Header <boost/core/noncopyable.hpp>] |
| 20 | |
| 21 | The header `<boost/core/noncopyable.hpp>` defines the class |
| 22 | `boost::noncopyable`. It is intended to be used as a private |
| 23 | base class. `boost::noncopyable` has private (under C++03) or |
| 24 | deleted (under C++11) copy constructor and a copy assignment |
| 25 | operator and can't be copied or assigned; a class that derives |
| 26 | from it inherits these properties. |
| 27 | |
| 28 | `boost::noncopyable` was originally contributed by Dave |
| 29 | Abrahams. |
| 30 | |
| 31 | [section Synopsis] |
| 32 | |
| 33 | `` |
| 34 | namespace boost |
| 35 | { |
| 36 | class noncopyable; |
| 37 | } |
| 38 | `` |
| 39 | |
| 40 | [endsect] |
| 41 | |
| 42 | [section Example] |
| 43 | |
| 44 | `` |
| 45 | #include <boost/core/noncopyable.hpp> |
| 46 | |
| 47 | class X: private boost::noncopyable |
| 48 | { |
| 49 | }; |
| 50 | `` |
| 51 | |
| 52 | [endsect] |
| 53 | |
| 54 | [section Rationale] |
| 55 | |
| 56 | Class noncopyable has protected constructor and destructor members to emphasize |
| 57 | that it is to be used only as a base class. Dave Abrahams notes concern about |
| 58 | the effect on compiler optimization of adding (even trivial inline) destructor |
| 59 | declarations. He says: |
| 60 | |
| 61 | ["Probably this concern is misplaced, because `noncopyable` will be used mostly |
| 62 | for classes which own resources and thus have non-trivial destruction semantics.] |
| 63 | |
| 64 | With C++2011, using an optimized and trivial constructor and similar destructor |
| 65 | can be enforced by declaring both and marking them `default`. This is done in |
| 66 | the current implementation. |
| 67 | |
| 68 | [endsect] |
| 69 | |
| 70 | [endsect] |
| 71 | |
| 72 | [endsect] |