boost/type_traits/is_abstract.hpp
#ifndef BOOST_TT_IS_ABSTRACT_CLASS_HPP
#define BOOST_TT_IS_ABSTRACT_CLASS_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
/////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
// is_abstract_class.hpp:
//
// (C) Copyright 2002 Rani Sharoni (rani_sharoni@hotmail.com) and Robert Ramey
// Use, modification and distribution is subject to 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 for updates, documentation, and revision history.
//
// Compile type discovery whether given type is abstract class or not.
//
// Requires DR 337 to be supported by compiler
// (http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/cwg_active.html#337).
//
//
// Believed (Jan 2004) to work on:
// - GCC 3.4
// - VC++ 7.1
// - compilers with new EDG frontend (Intel C++ 7, Comeau 4.3.2)
//
// Doesn't work on:
// - VC++6, VC++7.0 and less
// - GCC 3.3.X and less
// - Borland C++ 6 and less
//
//
// History:
// - Originally written by Rani Sharoni, see
// http://groups.google.com/groups?selm=df893da6.0207110613.75b2fe90%40posting.google.com
// At this time supported by EDG (Intel C++ 7, Comeau 4.3.2) and VC7.1.
// - Adapted and added into Boost.Serialization library by Robert Ramey
// (starting with submission #10).
// - Jan 2004: GCC 3.4 fixed to suport DR337 (Giovanni Bajo).
// - Jan 2004: modified to be part of Boost.TypeTraits (Pavel Vozenilek).
// - Nov 2004: Christoph Ludwig found that the implementation did not work with
// template types and gcc-3.4 or VC7.1, fix due to Christoph Ludwig
// and John Maddock.
// - Dec 2004: Added new config macro BOOST_NO_IS_ABSTRACT which causes the template
// to degrade gracefully, rather than trash the compiler (John Maddock).
//
#include <boost/type_traits/intrinsics.hpp>
#ifndef BOOST_IS_ABSTRACT
#include <boost/static_assert.hpp>
#include <boost/type_traits/detail/yes_no_type.hpp>
#include <boost/type_traits/is_class.hpp>
#include <boost/type_traits/detail/ice_and.hpp>
#ifdef BOOST_NO_IS_ABSTRACT
#include <boost/type_traits/is_polymorphic.hpp>
#endif
#endif
// should be the last #include
#include <boost/type_traits/detail/bool_trait_def.hpp>
namespace boost {
namespace detail{
#ifdef BOOST_IS_ABSTRACT
template <class T>
struct is_abstract_imp
{
BOOST_STATIC_CONSTANT(bool, value = BOOST_IS_ABSTRACT(T));
};
#elif !defined(BOOST_NO_IS_ABSTRACT)
template<class T>
struct is_abstract_imp2
{
// Deduction fails if T is void, function type,
// reference type (14.8.2/2)or an abstract class type
// according to review status issue #337
//
template<class U>
static type_traits::no_type check_sig(U (*)[1]);
template<class U>
static type_traits::yes_type check_sig(...);
//
// T must be a complete type, further if T is a template then
// it must be instantiated in order for us to get the right answer:
//
BOOST_STATIC_ASSERT(sizeof(T) != 0);
// GCC2 won't even parse this template if we embed the computation
// of s1 in the computation of value.
#ifdef __GNUC__
BOOST_STATIC_CONSTANT(std::size_t, s1 = sizeof(is_abstract_imp2<T>::template check_sig<T>(0)));
#else
#if BOOST_WORKAROUND(BOOST_MSVC_FULL_VER, >= 140050000)
#pragma warning(push)
#pragma warning(disable:6334)
#endif
BOOST_STATIC_CONSTANT(std::size_t, s1 = sizeof(check_sig<T>(0)));
#if BOOST_WORKAROUND(BOOST_MSVC_FULL_VER, >= 140050000)
#pragma warning(pop)
#endif
#endif
BOOST_STATIC_CONSTANT(bool, value =
(s1 == sizeof(type_traits::yes_type)));
};
template <bool v>
struct is_abstract_select
{
template <class T>
struct rebind
{
typedef is_abstract_imp2<T> type;
};
};
template <>
struct is_abstract_select<false>
{
template <class T>
struct rebind
{
typedef false_type type;
};
};
template <class T>
struct is_abstract_imp
{
typedef is_abstract_select< ::boost::is_class<T>::value> selector;
typedef typename selector::template rebind<T> binder;
typedef typename binder::type type;
BOOST_STATIC_CONSTANT(bool, value = type::value);
};
#endif
}
#ifndef BOOST_NO_IS_ABSTRACT
BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_abstract,T,::boost::detail::is_abstract_imp<T>::value)
#else
BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_abstract,T,::boost::detail::is_polymorphic_imp<T>::value)
#endif
} // namespace boost
#include <boost/type_traits/detail/bool_trait_undef.hpp>
#endif //BOOST_TT_IS_ABSTRACT_CLASS_HPP