...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::algorithm::one_of_equal
// In header: <boost/algorithm/cxx11/one_of.hpp> template<typename Range, typename V> BOOST_CXX14_CONSTEXPR bool one_of_equal(const Range & r, const V & val);