Function capacity

library/cpp/containers/cow_string/cow_string.h:176–182

    }

    inline size_t capacity() const noexcept {
        if (S_->IsNull()) {
            return 0;
        }

        return S_->capacity();
    }

    TCharType* Detach() Y_LIFETIME_BOUND {
        if (Y_UNLIKELY(!IsDetached())) {