Method operator!=

extlibs/fmt/include/fmt/core.h:421–423

    return lhs.compare(rhs) == 0;
  }
  friend bool operator!=(basic_string_view lhs, basic_string_view rhs) {
    return lhs.compare(rhs) != 0;
  }
  friend bool operator<(basic_string_view lhs, basic_string_view rhs) {
    return lhs.compare(rhs) < 0;
  }