Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for a snapshot of the master branch, built from commit a334065014.


/// \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


#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;

    // 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_abstract<T>
          , is_iostream<T>
          , is_base_of<noncopyable, T>

    template<typename T, std::size_t N>
    struct is_noncopyable<T[N]>
      : mpl::true_