| 3719 | |
| 3720 | template <typename T> |
| 3721 | class RepeatGenerator : public IGenerator<T> { |
| 3722 | GeneratorWrapper<T> m_generator; |
| 3723 | mutable std::vector<T> m_returned; |
| 3724 | size_t m_target_repeats; |
| 3725 | size_t m_current_repeat = 0; |
| 3726 | size_t m_repeat_index = 0; |
| 3727 | public: |
| 3728 | RepeatGenerator(size_t repeats, GeneratorWrapper<T>&& generator): |
| 3729 | m_generator(std::move(generator)), |
| 3730 | m_target_repeats(repeats) |
| 3731 | { |
| 3732 | assert(m_target_repeats > 0 && "Repeat generator must repeat at least once"); |
| 3733 | } |
| 3734 | |
| 3735 | T const& get() const override { |
| 3736 | if (m_current_repeat == 0) { |
| 3737 | m_returned.push_back(m_generator.get()); |
| 3738 | return m_returned.back(); |
| 3739 | } |
| 3740 | return m_returned[m_repeat_index]; |
| 3741 | } |
| 3742 | |
| 3743 | bool next() override { |
| 3744 | // There are 2 basic cases: |
| 3745 | // 1) We are still reading the generator |
| 3746 | // 2) We are reading our own cache |
| 3747 | |
| 3748 | // In the first case, we need to poke the underlying generator. |
| 3749 | // If it happily moves, we are left in that state, otherwise it is time to start reading from our cache |
| 3750 | if (m_current_repeat == 0) { |
| 3751 | const auto success = m_generator.next(); |
| 3752 | if (!success) { |
| 3753 | ++m_current_repeat; |
| 3754 | } |
| 3755 | return m_current_repeat < m_target_repeats; |
| 3756 | } |
| 3757 | |
| 3758 | // In the second case, we need to move indices forward and check that we haven't run up against the end |
| 3759 | ++m_repeat_index; |
| 3760 | if (m_repeat_index == m_returned.size()) { |
| 3761 | m_repeat_index = 0; |
| 3762 | ++m_current_repeat; |
| 3763 | } |
| 3764 | return m_current_repeat < m_target_repeats; |
| 3765 | } |
| 3766 | }; |
| 3767 | |
| 3768 | template <typename T> |
| 3769 | GeneratorWrapper<T> repeat(size_t repeats, GeneratorWrapper<T>&& generator) { |