detail::fixedstring::checkNullTerminated(that),
detail::fixedstring::checkOverflow(that_pos, M - 1u),
detail::fixedstring::checkOverflowOrNpos(that_count, M - 1u - that_pos),
detail::fixedstring::checkNullTerminated(that),
detail::fixedstring::checkOverflow(that_pos, M - 1u),
detail::fixedstring::checkOverflowOrNpos(that_count, M - 1u - that_pos),