/////////////////////////////////////////////////////////////////////////////// /// \file is_noncopyable.hpp /// Utility for detecting when types are non-copyable // // Copyright 2008 Eric Niebler. 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) #ifndef BOOST_PROTO_DETAIL_IS_NONCOPYABLE_HPP_EAN_19_07_2012 #define BOOST_PROTO_DETAIL_IS_NONCOPYABLE_HPP_EAN_19_07_2012 #include <boost/noncopyable.hpp> #include <boost/mpl/or.hpp> #include <boost/mpl/bool.hpp> #include <boost/type_traits/is_base_of.hpp> #include <boost/type_traits/is_abstract.hpp> #include <boost/type_traits/is_function.hpp> #include <boost/proto/proto_fwd.hpp> namespace boost { namespace proto { namespace detail { // All classes derived from std::ios_base have these public nested types, // and are non-copyable. This is an imperfect test, but it's the best we // we can do. template<typename T> yes_type check_is_iostream( typename T::failure * , typename T::Init * , typename T::fmtflags * , typename T::iostate * , typename T::openmode * , typename T::seekdir * ); template<typename T> no_type check_is_iostream(...); template<typename T> struct is_iostream { static bool const value = sizeof(yes_type) == sizeof(check_is_iostream<T>(0,0,0,0,0,0)); typedef mpl::bool_<value> type; }; /// INTERNAL ONLY // This should be a customization point. And it serves the same purpose // as the is_noncopyable trait in Boost.Foreach. template<typename T> struct is_noncopyable : mpl::or_< is_function<T> , is_abstract<T> , is_iostream<T> , is_base_of<noncopyable, T> > {}; template<typename T, std::size_t N> struct is_noncopyable<T[N]> : mpl::true_ {}; }}} #endif