[#E5DF77F30B30B7879D7ADA55F142FD6C3E4A0DCE]
Return the position of the first non-match
constexpr
size_type
find_first_not_of(
core::string_view str,
size_type pos = 0) const noexcept;
See `core::string_view::find_first_not_of`