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Workaround for EDG bug; improves encapsulation

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[SVN r21487]
This commit is contained in:
Dave Abrahams
2004-01-05 01:24:00 +00:00
parent 821c34d2dd
commit ac8bd8d5e8
1 changed files with 16 additions and 14 deletions
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30
include/boost/mpl/aux_/has_xxx.hpp
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@@ -33,23 +33,25 @@
# define BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(trait, name, unused) \
template< typename T > \
boost::mpl::aux::yes_tag \
trait##_helper( \
boost::mpl::aux::type_wrapper<T> const volatile* \
, boost::mpl::aux::type_wrapper<BOOST_MSVC_TYPENAME T::name>* = 0 \
); \
\
boost::mpl::aux::no_tag \
trait##_helper(...); \
\
template< typename T > \
struct trait \
{ \
template< typename U > \
static boost::mpl::aux::yes_tag \
helper( \
boost::mpl::aux::type_wrapper<U> const volatile* \
, boost::mpl::aux::type_wrapper<BOOST_MSVC_TYPENAME U::name>* = 0 \
); \
\
static boost::mpl::aux::no_tag \
helper(...); \
\
typedef boost::mpl::aux::type_wrapper<T> t_; \
BOOST_STATIC_CONSTANT(bool, value = \
sizeof((trait##_helper)(static_cast<t_*>(0))) \
== sizeof(boost::mpl::aux::yes_tag) \
); \
\
BOOST_STATIC_CONSTANT( \
bool, value = \
sizeof(trait<T>::helper(static_cast<t_*>(0))) \
== sizeof(boost::mpl::aux::yes_tag) \
); \
}; \
/**/