Brian Silverman | 4a2409e | 2018-08-04 23:24:02 -0700 | [diff] [blame^] | 1 | [/ |
| 2 | Copyright 2007 John Maddock. |
| 3 | Copyright 2013 Antony Polukhin. |
| 4 | Distributed under the Boost Software License, Version 1.0. |
| 5 | (See accompanying file LICENSE_1_0.txt or copy at |
| 6 | http://www.boost.org/LICENSE_1_0.txt). |
| 7 | ] |
| 8 | |
| 9 | [section:is_nothrow_move_assignable is_nothrow_move_assignable] |
| 10 | |
| 11 | template <class T> |
| 12 | struct is_nothrow_move_assignable : public __tof {}; |
| 13 | |
| 14 | __inherit If `T` is a (possibly cv-qualified) type with a non-throwing move assignment-operator |
| 15 | or a type without move assignment-operator but with non-throwing assignment-operator, |
| 16 | then inherits from __true_type, otherwise inherits from __false_type. Type `T` |
| 17 | must be a complete type. |
| 18 | |
| 19 | In other words, inherits from __true_type only if expression `variable1 = std::move(variable2)` |
| 20 | won't throw (`variable1` and `variable2` are variables of type `T`). |
| 21 | |
| 22 | __compat If the compiler does not support partial-specialization of class |
| 23 | templates, then this template can not be used with function types. |
| 24 | |
| 25 | Without some (C++11 noexcept shall work correctly) help from the compiler, |
| 26 | `is_nothrow_move_assignable` will never report that a class or struct has a |
| 27 | non-throwing assignment-operator; this is always safe, if possibly sub-optimal. |
| 28 | Currently (June 2015) MSVC-12.0, Clang and GCC 4.7 have the necessary compiler support to ensure that this |
| 29 | trait "just works". |
| 30 | |
| 31 | __header ` #include <boost/type_traits/is_nothrow_move_assignable.hpp>` or ` #include <boost/type_traits.hpp>` |
| 32 | |
| 33 | [endsect] |
| 34 | |