Realloc()/在C++中调整对象的大小以实现字符串实现

#include<iostream>
#include<string>

int main() {
    std::string str = "Hello, world!";
    std::cout << "Original string: "<< str<< std::endl;

    // 调整字符串大小
    str.resize(10);
    std::cout << "Resized string: "<< str<< std::endl;

    // 预留字符串大小
    str.reserve(20);
    std::cout << "Reserved string: "<< str<< std::endl;

    return 0;
}

Original string: Hello, world!
Resized string: Hello, wor
Reserved string: Hello, wor