...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::histogram::axis::traits::index — Returns axis index for value.
// In header: <boost/histogram/axis/traits.hpp> template<class... Ts, typename U> auto index(const variant< Ts... > & axis, const U & value);