Function DetachAndFixPointers

library/cpp/containers/cow_string/cow_string.cpp:50–55

template <class TStringType>
static void DetachAndFixPointers(TStringType& text, typename TStringType::value_type*& p, const typename TStringType::value_type*& pe) {
    const auto pos = p - text.data();
    const auto count = pe - p;
    p = text.Detach() + pos;
    pe = p + count;
}

template <class TStringType, typename F>
static bool ModifyStringSymbolwise(TStringType& text, size_t pos, size_t count, F&& f) {