소프트웨어 성능 튜닝에 C++를 사용하는 방법은 무엇입니까?

#include <unordered_map>
#include <iostream>

int main() {
    // 创建一个哈希表
    std::unordered_map<int, std::string> hashMap;

    // 添加元素到哈希表
    hashMap[1] = "apple";
    hashMap[2] = "banana";
    hashMap[3] = "orange";

    // 查找元素
    std::unordered_map<int, std::string>::iterator iter = hashMap.find(2);
    if (iter != hashMap.end()) {
        std::cout << "Found: " << iter->second << std::endl;
    }

    return 0;
}

#include <iostream>

class Object {
public:
    Object() { std::cout << "Construct Object" << std::endl; }
    ~Object() { std::cout << "Destruct Object" << std::endl; }
};

class ObjectPool {
public:
    Object* getObject() {
        if (m_freeObjects.empty()) {
            std::cout << "Allocate new Object" << std::endl;
            return new Object();
        } else {
            std::cout << "Reuse Object" << std::endl;
            Object* obj = m_freeObjects.back();
            m_freeObjects.pop_back();
            return obj;
        }
    }

    void releaseObject(Object* obj) {
        std::cout << "Release Object" << std::endl;
        m_freeObjects.push_back(obj);
    }

private:
    std::vector<Object*> m_freeObjects;
};

int main() {
    ObjectPool objectPool;

    Object* obj1 = objectPool.getObject();
    Object* obj2 = objectPool.getObject();

    objectPool.releaseObject(obj1);
    objectPool.releaseObject(obj2);

    return 0;
}

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

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

    std::sort(numbers.begin(), numbers.end());

    for (int number : numbers) {
        std::cout << number << " ";
    }

    return 0;
}

#include <iostream>
#include <string>
#include <utility>

void processString(std::string& str) {
    str += "processed";
}

void processStringWithMove(std::string&& str) {
    str += "processed";
    std::cout << str << std::endl;
}

int main() {
    std::string str = "input";

    processString(str);
    std::cout << str << std::endl;

    processStringWithMove(std::move(str));
    std::cout << str << std::endl; // 打印结果不确定，str可能为空

    return 0;
}