1
2// (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, Howard
3// Hinnant & John Maddock 2000.
4// Use, modification and distribution are subject to the Boost Software License,
5// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt).
7//
8// See http://www.boost.org/libs/type_traits for most recent version including documentation.
9
10
11#ifndef BOOST_TT_ADD_CV_HPP_INCLUDED
12#define BOOST_TT_ADD_CV_HPP_INCLUDED
13
14#include <boost/config.hpp>
15
16namespace boost {
17
18// * convert a type T to a const volatile type - add_cv<T>
19// this is not required since the result is always
20// the same as "T const volatile", but it does suppress warnings
21// from some compilers:
22
23#if defined(BOOST_MSVC)
24// This bogus warning will appear when add_volatile is applied to a
25// const volatile reference because we can't detect const volatile
26// references with MSVC6.
27# pragma warning(push)
28# pragma warning(disable:4181) // warning C4181: qualifier applied to reference type ignored
29#endif
30
31template <class T> struct add_cv{ typedef T const volatile type; };
32
33#if defined(BOOST_MSVC)
34# pragma warning(pop)
35#endif
36
37template <class T> struct add_cv<T&>{ typedef T& type; };
38
39#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
40
41 template <class T> using add_cv_t = typename add_cv<T>::type;
42
43#endif
44
45} // namespace boost
46
47#endif // BOOST_TT_ADD_CV_HPP_INCLUDED
48

source code of include/boost/type_traits/add_cv.hpp