...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
BOOST_TTI_HAS_DATA — Expands to a metafunction which tests whether member data or static member data with a particular name and type exists.
// In header: <boost/tti/has_data.hpp>
BOOST_TTI_HAS_DATA(name)
name = the name of the inner member.
generates a metafunction called "has_data_name" where 'name' is the macro parameter. template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_TYPE> struct has_data_name { static const value = unspecified; typedef mpl::bool_<true-or-false> type; }; The metafunction types and return: BOOST_TTI_TP_T = the enclosing type in which to look for our 'name' BOOST_TTI_TP_TYPE = The type of the member data or static member. returns = 'value' is true if the 'name' exists, with the correct data type, otherwise 'value' is false.