third_party/boost/type_traits/doc/add_reference.qbk

[/ 
  Copyright 2007 John Maddock.
  Distributed under the Boost Software License, Version 1.0.
  (See accompanying file LICENSE_1_0.txt or copy at
  http://www.boost.org/LICENSE_1_0.txt).
]

[section:add_reference add_reference]

[note This trait has been made obsolete by __add_lvalue_reference and __add_rvalue_reference, 
and new code should use these new traits rather than __is_reference which is retained
for backwards compatibility only.
]


   template <class T>
   struct add_reference
   {
      typedef __below type;
   };

   template <class T> using add_reference_t = typename add_reference<T>::type; // C++11 and above
  
__type If `T` is not a reference type then `T&`, otherwise `T`.

__std_ref 8.3.2.

__header ` #include <boost/type_traits/add_reference.hpp>` or ` #include <boost/type_traits.hpp>`

[table Examples

[ [Expression] [Result Type]]

[[`add_reference<int>::type`][`int&`]]

[[`add_reference<int const&>::type`] [`int const&`]]

[[`add_reference<int*>::type`] [`int*&`]]

[[`add_reference<int*&>::type`] [`int*&`]]

]

[all_compilers]

[endsect]