#include <boost/hana/core/when.hpp>
-BOOST_HANA_NAMESPACE_BEGIN
+namespace boost { namespace hana {
//! Return the number of elements in a foldable structure.
//! @ingroup group-Foldable
//!
constexpr auto operator()(Xs const& xs) const;
};
- constexpr length_t length{};
+ BOOST_HANA_INLINE_VARIABLE constexpr length_t length{};
#endif
-BOOST_HANA_NAMESPACE_END
+}} // end namespace boost::hana
#endif // !BOOST_HANA_FWD_LENGTH_HPP