#ifndef BOOST_MPL_HAS_XXX_HPP_INCLUDED #define BOOST_MPL_HAS_XXX_HPP_INCLUDED // Copyright Aleksey Gurtovoy 2002-2006 // Copyright David Abrahams 2002-2003 // Copyright Daniel Walker 2007 // // 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/mpl for documentation. // $Id$ // $Date$ // $Revision$ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if BOOST_WORKAROUND( BOOST_BORLANDC, BOOST_TESTED_AT(0x590) ) # include #endif #if !defined(BOOST_MPL_CFG_NO_HAS_XXX) # if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) // agurt, 11/sep/02: MSVC-specific version (< 7.1), based on a USENET // newsgroup's posting by John Madsen (comp.lang.c++.moderated, // 1999-11-12 19:17:06 GMT); the code is _not_ standard-conforming, but // it works way more reliably than the SFINAE-based implementation // Modified dwa 8/Oct/02 to handle reference types. # include # include namespace boost { namespace mpl { namespace aux { struct has_xxx_tag; #if BOOST_WORKAROUND(BOOST_MSVC, == 1300) template< typename U > struct msvc_incomplete_array { typedef char (&type)[sizeof(U) + 1]; }; #endif template< typename T > struct msvc_is_incomplete { // MSVC is capable of some kinds of SFINAE. If U is an incomplete // type, it won't pick the second overload static char tester(...); #if BOOST_WORKAROUND(BOOST_MSVC, == 1300) template< typename U > static typename msvc_incomplete_array::type tester(type_wrapper); #else template< typename U > static char (& tester(type_wrapper) )[sizeof(U)+1]; #endif BOOST_STATIC_CONSTANT(bool, value = sizeof(tester(type_wrapper())) == 1 ); }; template<> struct msvc_is_incomplete { BOOST_STATIC_CONSTANT(bool, value = false); }; }}} # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, default_) \ template< typename T, typename name = ::boost::mpl::aux::has_xxx_tag > \ struct BOOST_PP_CAT(trait,_impl) : T \ { \ static boost::mpl::aux::no_tag \ test(void(*)(::boost::mpl::aux::has_xxx_tag)); \ \ static boost::mpl::aux::yes_tag test(...); \ \ BOOST_STATIC_CONSTANT(bool, value = \ sizeof(test(static_cast(0))) \ != sizeof(boost::mpl::aux::no_tag) \ ); \ typedef boost::mpl::bool_ type; \ }; \ \ template< typename T, typename fallback_ = boost::mpl::bool_ > \ struct trait \ : boost::mpl::if_c< \ boost::mpl::aux::msvc_is_incomplete::value \ , boost::mpl::bool_ \ , BOOST_PP_CAT(trait,_impl) \ >::type \ { \ }; \ \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, void) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, bool) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, char) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed char) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned char) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed short) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned short) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed int) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned int) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, signed long) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, unsigned long) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, float) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, double) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, long double) \ /**/ # define BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, T) \ template<> struct trait \ { \ BOOST_STATIC_CONSTANT(bool, value = false); \ typedef boost::mpl::bool_ type; \ }; \ /**/ #if !defined(BOOST_NO_INTRINSIC_WCHAR_T) # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \ BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, unused) \ BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(trait, wchar_t) \ /**/ #else # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \ BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF_(trait, name, unused) \ /**/ #endif // SFINAE-based implementations below are derived from a USENET newsgroup's // posting by Rani Sharoni (comp.lang.c++.moderated, 2002-03-17 07:45:09 PST) # elif BOOST_WORKAROUND(BOOST_MSVC, <= 1400) \ || (BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1800)) && defined(__CUDACC__)) \ || BOOST_WORKAROUND(__IBMCPP__, <= 700) // MSVC 7.1 & MSVC 8.0 & VACPP // agurt, 15/jun/05: replace overload-based SFINAE implementation with SFINAE // applied to partial specialization to fix some apparently random failures // (thanks to Daniel Wallin for researching this!) # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \ template< typename T > \ struct BOOST_PP_CAT(trait, _msvc_sfinae_helper) \ { \ typedef void type; \ };\ \ template< typename T, typename U = void > \ struct BOOST_PP_CAT(trait,_impl_) \ { \ BOOST_STATIC_CONSTANT(bool, value = false); \ typedef boost::mpl::bool_ type; \ }; \ \ template< typename T > \ struct BOOST_PP_CAT(trait,_impl_)< \ T \ , typename BOOST_PP_CAT(trait, _msvc_sfinae_helper)< typename T::name >::type \ > \ { \ BOOST_STATIC_CONSTANT(bool, value = true); \ typedef boost::mpl::bool_ type; \ }; \ \ template< typename T, typename fallback_ = boost::mpl::bool_ > \ struct trait \ : BOOST_PP_CAT(trait,_impl_) \ { \ }; \ /**/ # elif BOOST_WORKAROUND( BOOST_BORLANDC, BOOST_TESTED_AT(0x590) ) # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_BCB_DEF(trait, trait_tester, name, default_) \ template< typename T, bool IS_CLASS > \ struct trait_tester \ { \ BOOST_STATIC_CONSTANT( bool, value = false ); \ }; \ template< typename T > \ struct trait_tester< T, true > \ { \ struct trait_tester_impl \ { \ template < class U > \ static int resolve( boost::mpl::aux::type_wrapper const volatile * \ , boost::mpl::aux::type_wrapper* = 0 ); \ static char resolve( ... ); \ }; \ typedef boost::mpl::aux::type_wrapper t_; \ BOOST_STATIC_CONSTANT( bool, value = ( sizeof( trait_tester_impl::resolve( static_cast< t_ * >(0) ) ) == sizeof(int) ) ); \ }; \ template< typename T, typename fallback_ = boost::mpl::bool_ > \ struct trait \ { \ BOOST_STATIC_CONSTANT( bool, value = (trait_tester< T, boost::is_class< T >::value >::value) ); \ typedef boost::mpl::bool_< trait< T, fallback_ >::value > type; \ }; # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \ BOOST_MPL_HAS_XXX_TRAIT_NAMED_BCB_DEF( trait \ , BOOST_PP_CAT(trait,_tester) \ , name \ , default_ ) \ /**/ # else // other SFINAE-capable compilers # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \ template< typename T, typename fallback_ = boost::mpl::bool_ > \ struct trait \ { \ struct gcc_3_2_wknd \ { \ template< typename U > \ static boost::mpl::aux::yes_tag test( \ boost::mpl::aux::type_wrapper const volatile* \ , boost::mpl::aux::type_wrapper* = 0 \ ); \ \ static boost::mpl::aux::no_tag test(...); \ }; \ \ typedef boost::mpl::aux::type_wrapper t_; \ BOOST_STATIC_CONSTANT(bool, value = \ sizeof(gcc_3_2_wknd::test(static_cast(0))) \ == sizeof(boost::mpl::aux::yes_tag) \ ); \ typedef boost::mpl::bool_ type; \ }; \ /**/ # endif // BOOST_WORKAROUND(BOOST_MSVC, <= 1300) #else // BOOST_MPL_CFG_NO_HAS_XXX // placeholder implementation # define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, default_) \ template< typename T, typename fallback_ = boost::mpl::bool_ > \ struct trait \ { \ BOOST_STATIC_CONSTANT(bool, value = fallback_::value); \ typedef fallback_ type; \ }; \ /**/ #endif #define BOOST_MPL_HAS_XXX_TRAIT_DEF(name) \ BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(BOOST_PP_CAT(has_,name), name, false) \ /**/ #if !defined(BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE) // Create a boolean Metafunction to detect a nested template // member. This implementation is based on a USENET newsgroup's // posting by Aleksey Gurtovoy (comp.lang.c++.moderated, 2002-03-19), // Rani Sharoni's USENET posting cited above, the non-template has_xxx // implementations above, and discussion on the Boost mailing list. # if !defined(BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES) # if BOOST_WORKAROUND(BOOST_MSVC, <= 1400) # define BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES 1 # else # define BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES 0 # endif # endif # if !defined(BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION) # if (defined(BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS)) # define BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION 1 # else # define BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION 0 # endif # endif # if !defined(BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE) # if BOOST_WORKAROUND(BOOST_MSVC, <= 1400) # define BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE 1 # else # define BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE 0 # endif # endif // NOTE: Many internal implementation macros take a Boost.Preprocessor // array argument called args which is of the following form. // ( 4, ( trait, name, max_arity, default_ ) ) # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args) \ BOOST_PP_CAT(BOOST_PP_ARRAY_ELEM(0, args) , _introspect) \ /**/ # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) \ BOOST_PP_CAT(BOOST_PP_CAT(BOOST_PP_ARRAY_ELEM(0, args) , _substitute), n) \ /**/ # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args) \ BOOST_PP_CAT(BOOST_PP_ARRAY_ELEM(0, args) , _test) \ /**/ // Thanks to Guillaume Melquiond for pointing out the need for the // "substitute" template as an argument to the overloaded test // functions to get SFINAE to work for member templates with the // correct name but different number of arguments. # define BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE(z, n, args) \ template< \ template< BOOST_PP_ENUM_PARAMS(BOOST_PP_INC(n), typename V) > class V \ > \ struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) { \ }; \ /**/ # define BOOST_MPL_HAS_MEMBER_SUBSTITUTE(args, substitute_macro) \ BOOST_PP_REPEAT( \ BOOST_PP_ARRAY_ELEM(2, args) \ , BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE \ , args \ ) \ /**/ # if !BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION # define BOOST_MPL_HAS_MEMBER_REJECT(args, member_macro) \ template< typename V > \ static boost::mpl::aux::no_tag \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)(...); \ /**/ # else # define BOOST_MPL_HAS_MEMBER_REJECT(args, member_macro) \ static boost::mpl::aux::no_tag \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)(...); \ /**/ # endif # if !BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES # define BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT(z, n, args) \ template< typename V > \ static boost::mpl::aux::yes_tag \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \ boost::mpl::aux::type_wrapper< V > const volatile* \ , BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) < \ V::template BOOST_PP_ARRAY_ELEM(1, args) \ >* = 0 \ ); \ /**/ # define BOOST_MPL_HAS_MEMBER_ACCEPT(args, member_macro) \ BOOST_PP_REPEAT( \ BOOST_PP_ARRAY_ELEM(2, args) \ , BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT \ , args \ ) \ /**/ # else # define BOOST_MPL_HAS_MEMBER_ACCEPT(args, member_macro) \ template< typename V > \ static boost::mpl::aux::yes_tag \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \ V const volatile* \ , member_macro(args, V, T)* = 0 \ ); \ /**/ # endif # if !BOOST_MPL_HAS_XXX_NO_EXPLICIT_TEST_FUNCTION # define BOOST_MPL_HAS_MEMBER_TEST(args) \ sizeof(BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)< U >(0)) \ == sizeof(boost::mpl::aux::yes_tag) \ /**/ # else # if !BOOST_MPL_HAS_XXX_NO_WRAPPED_TYPES # define BOOST_MPL_HAS_MEMBER_TEST(args) \ sizeof( \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \ static_cast< boost::mpl::aux::type_wrapper< U >* >(0) \ ) \ ) == sizeof(boost::mpl::aux::yes_tag) \ /**/ # else # define BOOST_MPL_HAS_MEMBER_TEST(args) \ sizeof( \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)( \ static_cast< U* >(0) \ ) \ ) == sizeof(boost::mpl::aux::yes_tag) \ /**/ # endif # endif # define BOOST_MPL_HAS_MEMBER_INTROSPECT( \ args, substitute_macro, member_macro \ ) \ template< typename U > \ struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args) { \ BOOST_MPL_HAS_MEMBER_SUBSTITUTE(args, substitute_macro) \ BOOST_MPL_HAS_MEMBER_REJECT(args, member_macro) \ BOOST_MPL_HAS_MEMBER_ACCEPT(args, member_macro) \ BOOST_STATIC_CONSTANT( \ bool, value = BOOST_MPL_HAS_MEMBER_TEST(args) \ ); \ typedef boost::mpl::bool_< value > type; \ }; \ /**/ # define BOOST_MPL_HAS_MEMBER_IMPLEMENTATION( \ args, introspect_macro, substitute_macro, member_macro \ ) \ template< \ typename T \ , typename fallback_ \ = boost::mpl::bool_< BOOST_PP_ARRAY_ELEM(3, args) > \ > \ class BOOST_PP_ARRAY_ELEM(0, args) { \ introspect_macro(args, substitute_macro, member_macro) \ public: \ static const bool value \ = BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args)< T >::value; \ typedef typename BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args)< \ T \ >::type type; \ }; \ /**/ // BOOST_MPL_HAS_MEMBER_WITH_FUNCTION_SFINAE expands to the full // implementation of the function-based metafunction. Compile with -E // to see the preprocessor output for this macro. # define BOOST_MPL_HAS_MEMBER_WITH_FUNCTION_SFINAE( \ args, substitute_macro, member_macro \ ) \ BOOST_MPL_HAS_MEMBER_IMPLEMENTATION( \ args \ , BOOST_MPL_HAS_MEMBER_INTROSPECT \ , substitute_macro \ , member_macro \ ) \ /**/ # if BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE # if !defined(BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE) # if BOOST_WORKAROUND(BOOST_MSVC, <= 1400) # define BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE 1 # endif # endif # if !BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \ args, n \ ) \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) \ /**/ # else # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \ args, n \ ) \ BOOST_PP_CAT( \ boost_mpl_has_xxx_ \ , BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME(args, n) \ ) \ /**/ # endif # define BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME( \ args \ ) \ BOOST_PP_CAT( \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \ args, 0 \ ) \ , _tag \ ) \ /**/ # define BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE_WITH_TEMPLATE_SFINAE( \ z, n, args \ ) \ template< \ template< BOOST_PP_ENUM_PARAMS(BOOST_PP_INC(n), typename U) > class U \ > \ struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \ args, n \ ) { \ typedef \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME(args) \ type; \ }; \ /**/ # define BOOST_MPL_HAS_MEMBER_SUBSTITUTE_WITH_TEMPLATE_SFINAE( \ args, substitute_macro \ ) \ typedef void \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME(args); \ BOOST_PP_REPEAT( \ BOOST_PP_ARRAY_ELEM(2, args) \ , BOOST_MPL_HAS_MEMBER_MULTI_SUBSTITUTE_WITH_TEMPLATE_SFINAE \ , args \ ) \ /**/ # define BOOST_MPL_HAS_MEMBER_REJECT_WITH_TEMPLATE_SFINAE( \ args, member_macro \ ) \ template< \ typename U \ , typename V \ = BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_TAG_NAME(args) \ > \ struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args) { \ BOOST_STATIC_CONSTANT(bool, value = false); \ typedef boost::mpl::bool_< value > type; \ }; \ /**/ # define BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT_WITH_TEMPLATE_SFINAE( \ z, n, args \ ) \ template< typename U > \ struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)< \ U \ , typename \ BOOST_MPL_HAS_MEMBER_INTROSPECTION_SUBSTITUTE_NAME_WITH_TEMPLATE_SFINAE( \ args, n \ )< \ BOOST_MSVC_TYPENAME U::BOOST_PP_ARRAY_ELEM(1, args)< > \ >::type \ > { \ BOOST_STATIC_CONSTANT(bool, value = true); \ typedef boost::mpl::bool_< value > type; \ }; \ /**/ # define BOOST_MPL_HAS_MEMBER_ACCEPT_WITH_TEMPLATE_SFINAE( \ args, member_macro \ ) \ BOOST_PP_REPEAT( \ BOOST_PP_ARRAY_ELEM(2, args) \ , BOOST_MPL_HAS_MEMBER_MULTI_ACCEPT_WITH_TEMPLATE_SFINAE \ , args \ ) \ /**/ # define BOOST_MPL_HAS_MEMBER_INTROSPECT_WITH_TEMPLATE_SFINAE( \ args, substitute_macro, member_macro \ ) \ BOOST_MPL_HAS_MEMBER_REJECT_WITH_TEMPLATE_SFINAE(args, member_macro) \ BOOST_MPL_HAS_MEMBER_ACCEPT_WITH_TEMPLATE_SFINAE(args, member_macro) \ template< typename U > \ struct BOOST_MPL_HAS_MEMBER_INTROSPECTION_NAME(args) \ : BOOST_MPL_HAS_MEMBER_INTROSPECTION_TEST_NAME(args)< U > { \ }; \ /**/ // BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE expands to the full // implementation of the template-based metafunction. Compile with -E // to see the preprocessor output for this macro. // // Note that if BOOST_MPL_HAS_XXX_NEEDS_NAMESPACE_LEVEL_SUBSTITUTE is // defined BOOST_MPL_HAS_MEMBER_SUBSTITUTE_WITH_TEMPLATE_SFINAE needs // to be expanded at namespace level before // BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE can be used. # define BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE( \ args, substitute_macro, member_macro \ ) \ BOOST_MPL_HAS_MEMBER_SUBSTITUTE_WITH_TEMPLATE_SFINAE( \ args, substitute_macro \ ) \ BOOST_MPL_HAS_MEMBER_IMPLEMENTATION( \ args \ , BOOST_MPL_HAS_MEMBER_INTROSPECT_WITH_TEMPLATE_SFINAE \ , substitute_macro \ , member_macro \ ) \ /**/ # endif // BOOST_MPL_HAS_XXX_NEEDS_TEMPLATE_SFINAE // Note: In the current implementation the parameter and access macros // are no longer expanded. # if !BOOST_WORKAROUND(BOOST_MSVC, <= 1400) # define BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF(trait, name, default_) \ BOOST_MPL_HAS_MEMBER_WITH_FUNCTION_SFINAE( \ ( 4, ( trait, name, BOOST_MPL_LIMIT_METAFUNCTION_ARITY, default_ ) ) \ , BOOST_MPL_HAS_MEMBER_TEMPLATE_SUBSTITUTE_PARAMETER \ , BOOST_MPL_HAS_MEMBER_TEMPLATE_ACCESS \ ) \ /**/ # else # define BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF(trait, name, default_) \ BOOST_MPL_HAS_MEMBER_WITH_TEMPLATE_SFINAE( \ ( 4, ( trait, name, BOOST_MPL_LIMIT_METAFUNCTION_ARITY, default_ ) ) \ , BOOST_MPL_HAS_MEMBER_TEMPLATE_SUBSTITUTE_PARAMETER \ , BOOST_MPL_HAS_MEMBER_TEMPLATE_ACCESS \ ) \ /**/ # endif #else // BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE // placeholder implementation # define BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF(trait, name, default_) \ template< typename T \ , typename fallback_ = boost::mpl::bool_< default_ > > \ struct trait { \ BOOST_STATIC_CONSTANT(bool, value = fallback_::value); \ typedef fallback_ type; \ }; \ /**/ #endif // BOOST_MPL_CFG_NO_HAS_XXX_TEMPLATE # define BOOST_MPL_HAS_XXX_TEMPLATE_DEF(name) \ BOOST_MPL_HAS_XXX_TEMPLATE_NAMED_DEF( \ BOOST_PP_CAT(has_, name), name, false \ ) \ /**/ #endif // BOOST_MPL_HAS_XXX_HPP_INCLUDED