moveclass示例

#include <iostream>
#include <algorithm>

class Buffer {
private:
    int* data_;
    size_t size_;
    
public:
    // 构造函数
    Buffer(size_t size = 0) : size_(size) {
        data_ = (size > 0) ? new int[size] : nullptr;
        std::cout << "构造 Buffer，大小: " << size_ << std::endl;
    }
    
    // 析构函数
    ~Buffer() {
        delete[] data_;
        std::cout << "析构 Buffer，大小: " << size_ << std::endl;
    }
    
    // 拷贝赋值
    Buffer& operator=(const Buffer& other) {
        std::cout << "拷贝赋值" << std::endl;
        if (this != &other) {
            delete[] data_;
            size_ = other.size_;
            data_ = (size_ > 0) ? new int[size_] : nullptr;
            std::copy(other.data_, other.data_ + size_, data_);
        }
        return *this;
    }
    
    // 移动赋值
    Buffer& operator=(Buffer && other) noexcept {
        std::cout << "移动赋值" << std::endl;
        if (this != &other) {
            delete[] data_;          // 释放当前资源
            
            // 窃取资源
            data_ = other.data_;
            size_ = other.size_;
            
            // 置空源对象
            other.data_ = nullptr;
            other.size_ = 0;
        }
        return *this;
    }
    
    // 获取大小
    size_t size() const { return size_; }
    
    // 获取数据指针
    int* data() const { return data_; }
};

int main() {
    Buffer buf1(100);        // 构造 buf1
    Buffer buf2;             // 构造空 buf2
    
    std::cout << "--- 拷贝赋值 ---" << std::endl;
    buf2 = buf1;             // 拷贝赋值
    std::cout << "buf1 大小: " << buf1.size() << std::endl;
    std::cout << "buf2 大小: " << buf2.size() << std::endl;
    
    std::cout << "--- 移动赋值 ---" << std::endl;
    Buffer buf3;
    buf3 = std::move(buf1);  // 移动赋值
    std::cout << "buf1 大小: " << buf1.size() << std::endl;  // 0
    std::cout << "buf3 大小: " << buf3.size() << std::endl;  // 100
    
    return 0;
}