diff options
Diffstat (limited to 'boost/hana/ext/boost/mpl/vector.hpp')
| -rw-r--r-- | boost/hana/ext/boost/mpl/vector.hpp | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/boost/hana/ext/boost/mpl/vector.hpp b/boost/hana/ext/boost/mpl/vector.hpp index 29e9972b5d..706c2dd06d 100644 --- a/boost/hana/ext/boost/mpl/vector.hpp +++ b/boost/hana/ext/boost/mpl/vector.hpp @@ -99,9 +99,25 @@ BOOST_HANA_NAMESPACE_BEGIN using vector_tag = ::boost::mpl::sequence_tag< ::boost::mpl::vector<>>::type; }}} + namespace mpl_detail { + // When `BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES` is not defined (e.g. on + // MSVC), different MPL sequences (like vector0 and vector1) have different + // tags, so we need to take that into account when we compare them. +#ifndef BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES + template <typename T1, typename T2> + struct is_same_mpl_vector_tag : std::false_type { }; + + template <template <long> class Tag, long x, long y> + struct is_same_mpl_vector_tag<Tag<x>, Tag<y>> : std::true_type { }; +#else + template <typename T1, typename T2> + struct is_same_mpl_vector_tag : std::is_same<T1, T2> { }; +#endif + } + template <typename T> struct tag_of<T, when< - std::is_same< + mpl_detail::is_same_mpl_vector_tag< typename ::boost::mpl::sequence_tag<T>::type, ::boost::mpl::sequence_tag< ::boost::mpl::vector<>>::type >::value |