[#1AEE400DFFDD4DD0A69E2B1BBBF0DA0B916D9434]
Return the position of the last non-match
constexpr
size_type
find_last_not_of(
char const* s,
size_type pos,
size_type n) const noexcept;
See `core::string_view::find_last_not_of`