在for_each上使用仿函数

#include <iostream>
#include <vector>
#include <algorithm>

// 仿函数类
class MyFunctor {
public:
    void operator()(int num) {
        std::cout << num << " ";
    }
};

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

    // 使用仿函数打印每个元素
    std::cout << "Print elements: ";
    std::for_each(nums.begin(), nums.end(), MyFunctor());
    std::cout << std::endl;

    // 使用仿函数修改每个元素的值
    std::cout << "Modified elements: ";
    std::for_each(nums.begin(), nums.end(), [](int& num) { num *= 2; });
    std::for_each(nums.begin(), nums.end(), MyFunctor());
    std::cout << std::endl;

    return 0;
}

Print elements: 1 2 3 4 5 
Modified elements: 2 4 6 8 10