...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::pfr::tuple_size_v
// In header: <boost/pfr/tuple_size.hpp> constexpr std::size_t tuple_size_v;
tuple_size_v
is a template variable that contains fields count in a T and works for any T that satisfies simple aggregate .
Example:
std::array<int, boost::pfr::tuple_size_v<my_structure> > a;