2 #ifndef BOOST_MPL_HAS_XXX_HPP_INCLUDED
3 #define BOOST_MPL_HAS_XXX_HPP_INCLUDED
5 // Copyright Aleksey Gurtovoy 2002-2006
6 // Copyright David Abrahams 2002-2003
7 // Copyright Daniel Walker 2007
9 // Distributed under the Boost Software License, Version 1.0.
10 // (See accompanying file LICENSE_1_0.txt or copy at
11 // http://www.boost.org/LICENSE_1_0.txt)
13 // See http://www.boost.org/libs/mpl for documentation.
15 // $Id: has_xxx.hpp 64146 2010-07-19 00:46:31Z djwalker $
16 // $Date: 2010-07-18 17:46:31 -0700 (Sun, 18 Jul 2010) $
19 #include <boost/mpl/bool.hpp>
20 #include <boost/mpl/aux_/na_spec.hpp>
21 #include <boost/mpl/aux_/type_wrapper.hpp>
22 #include <boost/mpl/aux_/yes_no.hpp>
23 #include <boost/mpl/aux_/config/gcc.hpp>
24 #include <boost/mpl/aux_/config/has_xxx.hpp>
25 #include <boost/mpl/aux_/config/msvc_typename.hpp>
26 #include <boost/mpl/aux_/config/msvc.hpp>
27 #include <boost/mpl/aux_/config/static_constant.hpp>
28 #include <boost/mpl/aux_/config/workaround.hpp>
30 #include <boost/preprocessor/array/elem.hpp>
31 #include <boost/preprocessor/cat.hpp>
32 #include <boost/preprocessor/control/if.hpp>
33 #include <boost/preprocessor/repetition/enum_params.hpp>
34 #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
36 #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x590) )
37 # include <boost/type_traits/is_class.hpp>
40 #if !defined(BOOST_MPL_CFG_NO_HAS_XXX)
42 # if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
44 // agurt, 11/sep/02: MSVC-specific version (< 7.1), based on a USENET
45 // newsgroup's posting by John Madsen (comp.lang.c++.moderated,
46 // 1999-11-12 19:17:06 GMT); the code is _not_ standard-conforming, but
47 // it works way more reliably than the SFINAE-based implementation
49 // Modified dwa 8/Oct/02 to handle reference types.
51 # include <boost/mpl/if.hpp>
52 # include <boost/mpl/bool.hpp>
54 namespace boost { namespace mpl { namespace aux {
58 #if BOOST_WORKAROUND(BOOST_MSVC, == 1300)
59 template< typename U > struct msvc_incomplete_array
61 typedef char (&type)[sizeof(U) + 1];
65 template< typename T >
66 struct msvc_is_incomplete
68 // MSVC is capable of some kinds of SFINAE. If U is an incomplete
69 // type, it won't pick the second overload
70 static char tester(...);
72 #if BOOST_WORKAROUND(BOOST_MSVC, == 1300)
73 template< typename U >
74 static typename msvc_incomplete_array<U>::type tester(type_wrapper<U>);
76 template< typename U >
77 static char (& tester(type_wrapper<U>) )[sizeof(U)+1];
80 BOOST_STATIC_CONSTANT(bool, value =
81 sizeof(tester(type_wrapper<T>())) == 1
86 struct msvc_is_incomplete<int>
88 BOOST_STATIC_CONSTANT(bool, value = false);
93 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, default_) \
94 template< typename T, typename name = ::boost::mpl::aux::has_xxx_tag > \
95 struct BOOST_PP_CAT(trait,_impl) : T \
97 static boost::mpl::aux::no_tag \
98 test(void(*)(::boost::mpl::aux::has_xxx_tag)); \
100 static boost::mpl::aux::yes_tag test(...); \
102 BOOST_STATIC_CONSTANT(bool, value = \
103 sizeof(test(static_cast<void(*)(name)>(0))) \
104 != sizeof(boost::mpl::aux::no_tag) \
106 typedef boost::mpl::bool_<value> type; \
109 template< typename T, typename fallback_ = boost::mpl::bool_<default_> > \
111 : boost::mpl::if_c< \
112 boost::mpl::aux::msvc_is_incomplete<T>::value \
113 , boost::mpl::bool_<false> \
114 , BOOST_PP_CAT(trait,_impl)<T> \
119 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, void) \
120 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, bool) \
121 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, char) \
122 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed char) \
123 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned char) \
124 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed short) \
125 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned short) \
126 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed int) \
127 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned int) \
128 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed long) \
129 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned long) \
130 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, float) \
131 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, double) \
132 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, long double) \
135 # define BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, T) \
136 template<> struct trait<T> \
138 BOOST_STATIC_CONSTANT(bool, value = false); \
139 typedef boost::mpl::bool_<false> type; \
143 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
144 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \
145 BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, unused) \
146 BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, wchar_t) \
149 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \
150 BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, unused) \
155 // SFINAE-based implementations below are derived from a USENET newsgroup's
156 // posting by Rani Sharoni (comp.lang.c++.moderated, 2002-03-17 07:45:09 PST)
158 # elif BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400)) \
159 || BOOST_WORKAROUND(__IBMCPP__, <= 700)
163 // agurt, 15/jun/05: replace overload-based SFINAE implementation with SFINAE
164 // applied to partial specialization to fix some apparently random failures
165 // (thanks to Daniel Wallin for researching this!)
167 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \
168 template< typename T > \
169 struct BOOST_PP_CAT(trait, _msvc_sfinae_helper) \
174 template< typename T, typename U = void > \
175 struct BOOST_PP_CAT(trait,_impl_) \
177 BOOST_STATIC_CONSTANT(bool, value = false); \
178 typedef boost::mpl::bool_<value> type; \
181 template< typename T > \
182 struct BOOST_PP_CAT(trait,_impl_)< \
184 , typename BOOST_PP_CAT(trait, _msvc_sfinae_helper)< typename T::name >::type \
187 BOOST_STATIC_CONSTANT(bool, value = true); \
188 typedef boost::mpl::bool_<value> type; \
191 template< typename T, typename fallback_ = boost::mpl::bool_<default_> > \
193 : BOOST_PP_CAT(trait,_impl_)<T> \
198 # elif BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x590) )
200 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_BCB_DEF(trait, trait_tester, name, default_) \
201 template< typename T, bool IS_CLASS > \
202 struct trait_tester \
204 BOOST_STATIC_CONSTANT( bool, value = false ); \
206 template< typename T > \
207 struct trait_tester< T, true > \
209 struct trait_tester_impl \
211 template < class U > \
212 static int resolve( boost::mpl::aux::type_wrapper<U> const volatile * \
213 , boost::mpl::aux::type_wrapper<typename U::name >* = 0 ); \
214 static char resolve( ... ); \
216 typedef boost::mpl::aux::type_wrapper<T> t_; \
217 BOOST_STATIC_CONSTANT( bool, value = ( sizeof( trait_tester_impl::resolve( static_cast< t_ * >(0) ) ) == sizeof(int) ) ); \
219 template< typename T, typename fallback_ = boost::mpl::bool_<default_> > \
222 BOOST_STATIC_CONSTANT( bool, value = (trait_tester< T, boost::is_class< T >::value >::value) ); \
223 typedef boost::mpl::bool_< trait< T, fallback_ >::value > type; \
226 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \
227 BOOST_MPL_HAS_XXX_TRAIT_NAMED_BCB_DEF( trait \
228 , BOOST_PP_CAT(trait,_tester) \
233 # else // other SFINAE-capable compilers
235 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \
236 template< typename T, typename fallback_ = boost::mpl::bool_<default_> > \
239 struct gcc_3_2_wknd \
241 template< typename U > \
242 static boost::mpl::aux::yes_tag test( \
243 boost::mpl::aux::type_wrapper<U> const volatile* \
244 , boost::mpl::aux::type_wrapper<BOOST_MSVC_TYPENAME U::name>* = 0 \
247 static boost::mpl::aux::no_tag test(...); \
250 typedef boost::mpl::aux::type_wrapper<T> t_; \
251 BOOST_STATIC_CONSTANT(bool, value = \
252 sizeof(gcc_3_2_wknd::test(static_cast<t_*>(0))) \
253 == sizeof(boost::mpl::aux::yes_tag) \
255 typedef boost::mpl::bool_<value> type; \
259 # endif // BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
262 #else // BOOST_MPL_CFG_NO_HAS_XXX
264 // placeholder implementation
266 # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \
267 template< typename T, typename fallback_ = boost::mpl::bool_<default_> > \
270 BOOST_STATIC_CONSTANT(bool, value = fallback_::value); \
271 typedef fallback_ type; \
277 #define BOOST_MPL_HAS_XXX_TRAIT_DEF(name) \
278 BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(BOOST_PP_CAT(has_,name), name, false) \
282 #if !defined(BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE)
284 // Create a boolean Metafunction to detect a nested template
285 // member. This implementation is based on a USENET newsgroup's
286 // posting by Aleksey Gurtovoy (comp.lang.c++.moderated, 2002-03-19),
287 // Rani Sharoni's USENET posting cited above, the non-template has_xxx
288 // implementations above, and discussion on the Boost mailing list.
290 # if !defined(BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES)
291 # if BOOST_WORKAROUND(BOOST_MSVC, <= 1400)
292 # define BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES 1
296 # if !defined(BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION)
297 # if (defined(BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS))
298 # define BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION 1
302 # if !defined(BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE)
303 # if BOOST_WORKAROUND(BOOST_MSVC, <= 1400)
304 # define BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE 1
308 // NOTE: Many internal implementation macros take a Boost.Preprocessor
309 // array argument called args which is of the following form.
310 // ( 4, ( trait, name, max_arity, default_ ) )
312 # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args) \
313 BOOST_PP_CAT(BOOST_PP_ARRAY_ELEM(0, args) , _introspect) \
316 # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) \
317 BOOST_PP_CAT(BOOST_PP_CAT(BOOST_PP_ARRAY_ELEM(0, args) , _substitute), n) \
320 # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args) \
321 BOOST_PP_CAT(BOOST_PP_ARRAY_ELEM(0, args) , _test) \
324 // Thanks to Guillaume Melquiond for pointing out the need for the
325 // "substitute" template as an argument to the overloaded test
326 // functions to get SFINAE to work for member templates with the
327 // correct name but different number of arguments.
328 # define BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE(z, n, args) \
330 template< BOOST_PP_ENUM_PARAMS(BOOST_PP_INC(n), typename V) > class V \
332 struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) { \
336 # define BOOST_MPL_HAS_MEMBER_SUBSTITUTE(args, substitute_macro) \
338 BOOST_PP_ARRAY_ELEM(2, args) \
339 , BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE \
344 # if !BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION
345 # define BOOST_MPL_HAS_MEMBER_REJECT(args, member_macro) \
346 template< typename V > \
347 static boost::mpl::aux::no_tag \
348 BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)(...); \
351 # define BOOST_MPL_HAS_MEMBER_REJECT(args, member_macro) \
352 static boost::mpl::aux::no_tag \
353 BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)(...); \
357 # if !BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES
358 # define BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT(z, n, args) \
359 template< typename V > \
360 static boost::mpl::aux::yes_tag \
361 BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \
362 boost::mpl::aux::type_wrapper< V > const volatile* \
363 , BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) < \
364 V::template BOOST_PP_ARRAY_ELEM(1, args) \
368 # define BOOST_MPL_HAS_MEMBER_ACCEPT(args, member_macro) \
370 BOOST_PP_ARRAY_ELEM(2, args) \
371 , BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT \
376 # define BOOST_MPL_HAS_MEMBER_ACCEPT(args, member_macro) \
377 template< typename V > \
378 static boost::mpl::aux::yes_tag \
379 BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \
381 , member_macro(args, V, T)* = 0 \
386 # if !BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION
387 # define BOOST_MPL_HAS_MEMBER_TEST(args) \
388 sizeof(BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)< U >(0)) \
389 == sizeof(boost::mpl::aux::yes_tag) \
392 # if !BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES
393 # define BOOST_MPL_HAS_MEMBER_TEST(args) \
395 BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \
396 static_cast< boost::mpl::aux::type_wrapper< U >* >(0) \
398 ) == sizeof(boost::mpl::aux::yes_tag) \
401 # define BOOST_MPL_HAS_MEMBER_TEST(args) \
403 BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \
404 static_cast< U* >(0) \
406 ) == sizeof(boost::mpl::aux::yes_tag) \
411 # define BOOST_MPL_HAS_MEMBER_INTROSPECT( \
412 args, substitute_macro, member_macro \
414 template< typename U > \
415 struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args) { \
416 BOOST_MPL_HAS_MEMBER_SUBSTITUTE(args, substitute_macro) \
417 BOOST_MPL_HAS_MEMBER_REJECT(args, member_macro) \
418 BOOST_MPL_HAS_MEMBER_ACCEPT(args, member_macro) \
419 BOOST_STATIC_CONSTANT( \
420 bool, value = BOOST_MPL_HAS_MEMBER_TEST(args) \
422 typedef boost::mpl::bool_< value > type; \
426 # define BOOST_MPL_HAS_MEMBER_IMPLEMENTATION( \
427 args, introspect_macro, substitute_macro, member_macro \
431 , typename fallback_ \
432 = boost::mpl::bool_< BOOST_PP_ARRAY_ELEM(3, args) > \
434 class BOOST_PP_ARRAY_ELEM(0, args) { \
435 introspect_macro(args, substitute_macro, member_macro) \
437 static const bool value \
438 = BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args)< T >::value; \
439 typedef typename BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args)< \
445 // BOOST_MPL_HAS_MEMBER_WITH_FUNCTION_SFINAE expands to the full
446 // implementation of the function-based metafunction. Compile with -E
447 // to see the preprocessor output for this macro.
448 # define BOOST_MPL_HAS_MEMBER_WITH_FUNCTION_SFINAE( \
449 args, substitute_macro, member_macro \
451 BOOST_MPL_HAS_MEMBER_IMPLEMENTATION( \
453 , BOOST_MPL_HAS_MEMBER_INTROSPECT \
459 # if BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE
461 # if !defined(BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE)
462 # if BOOST_WORKAROUND(BOOST_MSVC, <= 1400)
463 # define BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE 1
467 # if !BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE
468 # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \
471 BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) \
474 # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \
479 , BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) \
484 # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME( \
488 BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \
495 # define BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE_WITH_TEMPLATE_SFINAE( \
499 template< BOOST_PP_ENUM_PARAMS(BOOST_PP_INC(n), typename U) > class U \
501 struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \
505 BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME(args) \
510 # define BOOST_MPL_HAS_MEMBER_SUBSTITUTE_WITH_TEMPLATE_SFINAE( \
511 args, substitute_macro \
514 BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME(args); \
516 BOOST_PP_ARRAY_ELEM(2, args) \
517 , BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE_WITH_TEMPLATE_SFINAE \
522 # define BOOST_MPL_HAS_MEMBER_REJECT_WITH_TEMPLATE_SFINAE( \
528 = BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME(args) \
530 struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args) { \
531 BOOST_STATIC_CONSTANT(bool, value = false); \
532 typedef boost::mpl::bool_< value > type; \
536 # define BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT_WITH_TEMPLATE_SFINAE( \
539 template< typename U > \
540 struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)< \
543 BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \
546 BOOST_MSVC_TYPENAME U::BOOST_PP_ARRAY_ELEM(1, args)< > \
549 BOOST_STATIC_CONSTANT(bool, value = true); \
550 typedef boost::mpl::bool_< value > type; \
554 # define BOOST_MPL_HAS_MEMBER_ACCEPT_WITH_TEMPLATE_SFINAE( \
558 BOOST_PP_ARRAY_ELEM(2, args) \
559 , BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT_WITH_TEMPLATE_SFINAE \
564 # define BOOST_MPL_HAS_MEMBER_INTROSPECT_WITH_TEMPLATE_SFINAE( \
565 args, substitute_macro, member_macro \
567 BOOST_MPL_HAS_MEMBER_REJECT_WITH_TEMPLATE_SFINAE(args, member_macro) \
568 BOOST_MPL_HAS_MEMBER_ACCEPT_WITH_TEMPLATE_SFINAE(args, member_macro) \
569 template< typename U > \
570 struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args) \
571 : BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)< U > { \
575 // BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE expands to the full
576 // implementation of the template-based metafunction. Compile with -E
577 // to see the preprocessor output for this macro.
579 // Note that if BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE is
580 // defined BOOST_MPL_HAS_MEMBER_SUBSTITUTE_WITH_TEMPLATE_SFINAE needs
581 // to be expanded at namespace level before
582 // BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE can be used.
583 # define BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE( \
584 args, substitute_macro, member_macro \
586 BOOST_MPL_HAS_MEMBER_SUBSTITUTE_WITH_TEMPLATE_SFINAE( \
587 args, substitute_macro \
589 BOOST_MPL_HAS_MEMBER_IMPLEMENTATION( \
591 , BOOST_MPL_HAS_MEMBER_INTROSPECT_WITH_TEMPLATE_SFINAE \
597 # endif // BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE
599 // Note: In the current implementation the parameter and access macros
600 // are no longer expanded.
601 # if !BOOST_WORKAROUND(BOOST_MSVC, <= 1400)
602 # define BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF(trait, name, default_) \
603 BOOST_MPL_HAS_MEMBER_WITH_FUNCTION_SFINAE( \
604 ( 4, ( trait, name, BOOST_MPL_LIMIT_METAFUNCTION_ARITY, default_ ) ) \
605 , BOOST_MPL_HAS_MEMBER_TEMPLATE_SUBSTITUTE_PARAMETER \
606 , BOOST_MPL_HAS_MEMBER_TEMPLATE_ACCESS \
610 # define BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF(trait, name, default_) \
611 BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE( \
612 ( 4, ( trait, name, BOOST_MPL_LIMIT_METAFUNCTION_ARITY, default_ ) ) \
613 , BOOST_MPL_HAS_MEMBER_TEMPLATE_SUBSTITUTE_PARAMETER \
614 , BOOST_MPL_HAS_MEMBER_TEMPLATE_ACCESS \
619 #else // BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE
621 // placeholder implementation
623 # define BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF(trait, name, default_) \
624 template< typename T \
625 , typename fallback_ = boost::mpl::bool_< default_ > > \
627 BOOST_STATIC_CONSTANT(bool, value = fallback_::value); \
628 typedef fallback_ type; \
632 #endif // BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE
634 # define BOOST_MPL_HAS_XXX_TEMPLATE_DEF(name) \
635 BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF( \
636 BOOST_PP_CAT(has_, name), name, false \
640 #endif // BOOST_MPL_HAS_XXX_HPP_INCLUDED