...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Return the position of the last non-match.
constexpr size_type find_last_not_of( char const* s, size_type pos = core::string_view::npos) const;
See core::string_view::find_last_not_of