boost/type_traits/add_cv.hpp

0001
0002 //  (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, Howard
0003 //  Hinnant & John Maddock 2000.
0004 //  Use, modification and distribution are subject to the Boost Software License,
0005 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
0006 //  http://www.boost.org/LICENSE_1_0.txt).
0007 //
0008 //  See http://www.boost.org/libs/type_traits for most recent version including documentation.
0009
0010
0011 #ifndef BOOST_TT_ADD_CV_HPP_INCLUDED
0012 #define BOOST_TT_ADD_CV_HPP_INCLUDED
0013
0014 #include <boost/config.hpp>
0015
0016 namespace boost {
0017
0018 // * convert a type T to a const volatile type - add_cv<T>
0019 // this is not required since the result is always
0020 // the same as "T const volatile", but it does suppress warnings
0021 // from some compilers:
0022
0023 #if defined(BOOST_MSVC)
0024 // This bogus warning will appear when add_volatile is applied to a
0025 // const volatile reference because we can't detect const volatile
0026 // references with MSVC6.
0027 #   pragma warning(push)
0028 #   pragma warning(disable:4181) // warning C4181: qualifier applied to reference type ignored
0029 #endif
0030
0031 template <class T> struct add_cv{ typedef T const volatile type; };
0032
0033 #if defined(BOOST_MSVC)
0034 #   pragma warning(pop)
0035 #endif
0036
0037 template <class T> struct add_cv<T&>{ typedef T& type; };
0038
0039 #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES)
0040
0041    template <class T> using add_cv_t = typename add_cv<T>::type;
0042
0043 #endif
0044
0045 } // namespace boost
0046
0047 #endif // BOOST_TT_ADD_CV_HPP_INCLUDED