1 #ifndef BOOST_TT_IS_ABSTRACT_CLASS_HPP
2 #define BOOST_TT_IS_ABSTRACT_CLASS_HPP
4 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
8 /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
9 // is_abstract_class.hpp:
11 // (C) Copyright 2002 Rani Sharoni (rani_sharoni@hotmail.com) and Robert Ramey
12 // Use, modification and distribution is subject to the Boost Software
13 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
14 // http://www.boost.org/LICENSE_1_0.txt)
16 // See http://www.boost.org for updates, documentation, and revision history.
19 // Compile type discovery whether given type is abstract class or not.
21 // Requires DR 337 to be supported by compiler
22 // (http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/cwg_active.html#337).
25 // Believed (Jan 2004) to work on:
28 // - compilers with new EDG frontend (Intel C++ 7, Comeau 4.3.2)
31 // - VC++6, VC++7.0 and less
32 // - GCC 3.3.X and less
33 // - Borland C++ 6 and less
37 // - Originally written by Rani Sharoni, see
38 // http://groups.google.com/groups?selm=df893da6.0207110613.75b2fe90%40posting.google.com
39 // At this time supported by EDG (Intel C++ 7, Comeau 4.3.2) and VC7.1.
40 // - Adapted and added into Boost.Serialization library by Robert Ramey
41 // (starting with submission #10).
42 // - Jan 2004: GCC 3.4 fixed to suport DR337 (Giovanni Bajo).
43 // - Jan 2004: modified to be part of Boost.TypeTraits (Pavel Vozenilek).
44 // - Nov 2004: Christoph Ludwig found that the implementation did not work with
45 // template types and gcc-3.4 or VC7.1, fix due to Christoph Ludwig
47 // - Dec 2004: Added new config macro BOOST_NO_IS_ABSTRACT which causes the template
48 // to degrade gracefully, rather than trash the compiler (John Maddock).
51 #include <boost/static_assert.hpp>
52 #include <boost/type_traits/detail/yes_no_type.hpp>
53 #include <boost/type_traits/is_class.hpp>
54 #include "boost/type_traits/detail/ice_and.hpp"
55 #ifdef BOOST_NO_IS_ABSTRACT
56 #include <boost/type_traits/is_polymorphic.hpp>
58 // should be the last #include
59 #include "boost/type_traits/detail/bool_trait_def.hpp"
65 #ifndef BOOST_NO_IS_ABSTRACT
67 struct is_abstract_imp2
69 // Deduction fails if T is void, function type,
70 // reference type (14.8.2/2)or an abstract class type
71 // according to review status issue #337
74 static type_traits::no_type check_sig(U (*)[1]);
76 static type_traits::yes_type check_sig(...);
78 // T must be a complete type, further if T is a template then
79 // it must be instantiated in order for us to get the right answer:
81 BOOST_STATIC_ASSERT(sizeof(T) != 0);
83 // GCC2 won't even parse this template if we embed the computation
84 // of s1 in the computation of value.
86 BOOST_STATIC_CONSTANT(unsigned, s1 = sizeof(is_abstract_imp2<T>::template check_sig<T>(0)));
88 BOOST_STATIC_CONSTANT(unsigned, s1 = sizeof(check_sig<T>(0)));
91 BOOST_STATIC_CONSTANT(bool, value =
92 (s1 == sizeof(type_traits::yes_type)));
96 struct is_abstract_select
101 typedef is_abstract_imp2<T> type;
105 struct is_abstract_select<false>
110 typedef false_type type;
115 struct is_abstract_imp
117 typedef is_abstract_select< ::boost::is_class<T>::value> selector;
118 typedef typename selector::template rebind<T> binder;
119 typedef typename binder::type type;
121 BOOST_STATIC_CONSTANT(bool, value = type::value);
127 #ifndef BOOST_NO_IS_ABSTRACT
128 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_abstract,T,::boost::detail::is_abstract_imp<T>::value)
130 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_abstract,T,::boost::detail::is_polymorphic_imp<T>::value)
135 #include "boost/type_traits/detail/bool_trait_undef.hpp"
137 #endif //BOOST_TT_IS_ABSTRACT_CLASS_HPP