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// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
// (C) Copyright 2003-2007 Jonathan Turkanis
// 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.)
// See http://www.boost.org/libs/iostreams for documentation.
// Contains the definition of the class template access_control, which
// allows the type of inheritance from a provided base class to be specified
// using a template parameter.
#ifndef NDNBOOST_IOSTREAMS_ACCESS_CONTROL_HPP_INCLUDED
#define NDNBOOST_IOSTREAMS_ACCESS_CONTROL_HPP_INCLUDED
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
#include <ndnboost/iostreams/detail/select.hpp>
#include <ndnboost/mpl/identity.hpp>
#include <ndnboost/type_traits/is_same.hpp>
namespace ndnboost { namespace iostreams {
struct protected_ { }; // Represents protected inheritance.
struct public_ { }; // Represents public inheritance.
namespace detail {
// Implements protected inheritance.
template<typename U>
struct prot_ : protected U
{
prot_() { }
template<typename V> prot_(V v) : U(v) { }
};
// Implements public inheritance.
template<typename U> struct pub_ : public U {
pub_() { }
template<typename V> pub_(V v) : U(v) { }
};
//
// Used to deduce the base type for the template access_control.
//
template<typename T, typename Access>
struct access_control_base {
typedef int bad_access_specifier;
typedef typename
iostreams::select< // Disambiguation for Tru64
::ndnboost::is_same<
Access, protected_
>, prot_<T>,
::ndnboost::is_same<
Access, public_
>, pub_<T>,
else_, bad_access_specifier
>::type type;
};
} // End namespace detail.
//
// Template name: access_control.
// Description: Allows the type of inheritance from a provided base class
// to be specified using an int template parameter.
// Template parameters:
// Base - The class from which to inherit (indirectly.)
// Access - The type of access desired. Must be one of the
// values access_base::prot or access_base::pub.
//
template< typename T, typename Access,
typename Base = // VC6 workaraound (Compiler Error C2516)
typename detail::access_control_base<T, Access>::type >
struct access_control : public Base {
access_control() { }
template<typename U> explicit access_control(U u) : Base(u) { }
};
//----------------------------------------------------------------------------//
} } // End namespaces iostreams, boost.
#endif // #ifndef NDNBOOST_IOSTREAMS_ACCESS_CONTROL_HPP_INCLUDED