Brian Silverman | 4a2409e | 2018-08-04 23:24:02 -0700 | [diff] [blame^] | 1 | [/ |
| 2 | Copyright 2007 John Maddock. |
| 3 | Distributed under the Boost Software License, Version 1.0. |
| 4 | (See accompanying file LICENSE_1_0.txt or copy at |
| 5 | http://www.boost.org/LICENSE_1_0.txt). |
| 6 | ] |
| 7 | |
| 8 | [section:add_reference add_reference] |
| 9 | |
| 10 | [note This trait has been made obsolete by __add_lvalue_reference and __add_rvalue_reference, |
| 11 | and new code should use these new traits rather than __is_reference which is retained |
| 12 | for backwards compatibility only. |
| 13 | ] |
| 14 | |
| 15 | |
| 16 | template <class T> |
| 17 | struct add_reference |
| 18 | { |
| 19 | typedef __below type; |
| 20 | }; |
| 21 | |
| 22 | template <class T> using add_reference_t = typename add_reference<T>::type; // C++11 and above |
| 23 | |
| 24 | __type If `T` is not a reference type then `T&`, otherwise `T`. |
| 25 | |
| 26 | __std_ref 8.3.2. |
| 27 | |
| 28 | __header ` #include <boost/type_traits/add_reference.hpp>` or ` #include <boost/type_traits.hpp>` |
| 29 | |
| 30 | [table Examples |
| 31 | |
| 32 | [ [Expression] [Result Type]] |
| 33 | |
| 34 | [[`add_reference<int>::type`][`int&`]] |
| 35 | |
| 36 | [[`add_reference<int const&>::type`] [`int const&`]] |
| 37 | |
| 38 | [[`add_reference<int*>::type`] [`int*&`]] |
| 39 | |
| 40 | [[`add_reference<int*&>::type`] [`int*&`]] |
| 41 | |
| 42 | ] |
| 43 | |
| 44 | [all_compilers] |
| 45 | |
| 46 | [endsect] |
| 47 | |