循环使用以第二个(或第n个)项开头的C++迭代器

#include<iostream>
#include<vector>

template<typename T>
class CircularIterator {
public:
    CircularIterator(const std::vector<T>& data, size_t start_index)
        : data_(data), index_(start_index) {}

    CircularIterator& operator++() {
        index_ = (index_ + 1) % data_.size();
        return *this;
    }

    T& operator*() {
        return data_[index_];
    }

private:
    const std::vector<T>& data_;
    size_t index_;
};

int main() {
    std::vector<int> data = {1, 2, 3, 4, 5};

    CircularIterator<int> iter(data, 1); // 从第二个项开始循环

    for (int i = 0; i < 10; ++i) {
        std::cout << *iter << " ";
        ++iter;
    }

    return 0;
}