2 // (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes,
3 // Howard Hinnant and John Maddock 2000.
4 // (C) Copyright Mat Marcus, Jesse Jones and Adobe Systems Inc 2001
6 // Use, modification and distribution are subject to the Boost Software License,
7 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
8 // http://www.boost.org/LICENSE_1_0.txt).
10 // See http://www.boost.org/libs/type_traits for most recent version including documentation.
12 // Fixed is_pointer, is_reference, is_const, is_volatile, is_same,
13 // is_member_pointer based on the Simulated Partial Specialization work
14 // of Mat Marcus and Jesse Jones. See http://opensource.adobe.com or
15 // http://groups.yahoo.com/group/boost/message/5441
16 // Some workarounds in here use ideas suggested from "Generic<Programming>:
17 // Mappings between Types and Values"
18 // by Andrei Alexandrescu (see http://www.cuj.com/experts/1810/alexandr.html).
21 #ifndef BOOST_TT_IS_REFERENCE_HPP_INCLUDED
22 #define BOOST_TT_IS_REFERENCE_HPP_INCLUDED
24 #include "boost/type_traits/config.hpp"
26 #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
27 # include "boost/type_traits/detail/yes_no_type.hpp"
28 # include "boost/type_traits/detail/wrap.hpp"
31 #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) && defined(BOOST_MSVC)
32 # include "boost/type_traits/detail/is_function_type_tester.hpp"
33 # include "boost/type_traits/detail/false_result.hpp"
36 // should be the last #include
37 #include "boost/type_traits/detail/bool_trait_def.hpp"
41 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
43 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_reference,T,false)
44 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T&,true)
46 #if defined(__BORLANDC__) && !defined(__COMO__) && (__BORLANDC__ < 0x600)
47 // these are illegal specialisations; cv-qualifies applied to
48 // references have no effect according to [8.3.2p1],
49 // C++ Builder requires them though as it treats cv-qualified
50 // references as distinct types...
51 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T& const,true)
52 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T& volatile,true)
53 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T& const volatile,true)
56 #if defined(__GNUC__) && (__GNUC__ < 3)
57 // these allow us to work around illegally cv-qualified reference
59 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T const ,::boost::is_reference<T>::value)
60 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T volatile ,::boost::is_reference<T>::value)
61 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_1(typename T,is_reference,T const volatile ,::boost::is_reference<T>::value)
62 // However, the above specializations confuse gcc 2.96 unless we also
63 // supply these specializations for array types
64 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,T[N],false)
65 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,const T[N],false)
66 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,volatile T[N],false)
67 BOOST_TT_AUX_BOOL_TRAIT_PARTIAL_SPEC1_2(typename T,unsigned long N,is_reference,const volatile T[N],false)
73 # pragma warning(push)
74 # pragma warning(disable: 4181)
79 using ::boost::type_traits::yes_type;
80 using ::boost::type_traits::no_type;
81 using ::boost::type_traits::wrap;
83 template <class T> T&(* is_reference_helper1(wrap<T>) )(wrap<T>);
84 char is_reference_helper1(...);
86 template <class T> no_type is_reference_helper2(T&(*)(wrap<T>));
87 yes_type is_reference_helper2(...);
90 struct is_reference_impl
92 BOOST_STATIC_CONSTANT(
94 ::boost::detail::is_reference_helper2(
95 ::boost::detail::is_reference_helper1(::boost::type_traits::wrap<T>()))) == 1
99 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void,false)
100 #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
101 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void const,false)
102 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void volatile,false)
103 BOOST_TT_AUX_BOOL_TRAIT_IMPL_SPEC1(is_reference,void const volatile,false)
106 } // namespace detail
108 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_reference,T,::boost::detail::is_reference_impl<T>::value)
111 # pragma warning(pop)
114 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
118 #include "boost/type_traits/detail/bool_trait_undef.hpp"
120 #endif // BOOST_TT_IS_REFERENCE_HPP_INCLUDED