```cppQuestion 8What will the output be for the following code?#include #include #include using namespace std;class Student {private: string m_name; shared_ptr m_pFriend;public: Student(string name) : m_name(name) { } void makeFriend(shared_ptr f) { m_pFriend=f; }};void mystery(shared_ptr p) { cout << "ref count: " << p.use_count() << endl; p->makeFriend(p); weak_ptr wpS = p; auto p2 = wpS.lock(); cout << "ref count: " << p.use_count() << endl;}int main() { auto pS(make_shared("Ellise")); cout << "ref count: " << pS.use_count() << endl; mystery(pS); cout << "ref count: " << pS.use_count() << endl; return 0;}```### ExplanationThis code is a C++ program that demonstrates the use of `shared_ptr` and `weak_ptr` from the C++ Standard Library. The `Student` class contains a `shared_ptr` to another `Student` object to manage friendships. The `mystery` function manipulates a `shared_ptr`, showing how reference counting works.#### Key Concepts:- **Shared Pointer (`shared_ptr`)**: A smart pointer retaining shared ownership of an object and managing its lifetime through reference counting. - **Weak Pointer (`weak_ptr`)**: A non-owning smart pointer used to break circular references by not contributing to the reference count.#### Program Flow:1. The program creates a `Student` object named "Ellise" using `make_shared`.2. It prints the initial reference count for the `pS` pointer.3. The `mystery` function is called, which: - Shows the reference count after passing `pS`. - Sets the student's friend to itself, potentially creating a cycle. - Instantiates a `weak_ptr` to demonstrate its non-ownership nature. - Prints the reference count after using `weak_ptr`.4. Finally, the program prints the reference count for `pS` again.#### Expected Output:- **First Output:** Initial reference count (`1`) for the `pS` pointer.- **Second Output

Answered: What will the output be for the…

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Related questions

Question

Expert Solution

Step 1

Given

C++ code

# include <string>
# include <iostream>
# include <memory>

using namespace std;

class Student {
private:
string m_name;
shared_ptr<Student> m_pFriend;
public:
Student(string name) : m_name(name) { }
void makeFriend(shared_ptr<Student> f) {m_pFriend=f;}
};

void mystery(shared_ptr<Student> p)
{
cout<<"ref count: "<<p.use_count() <<endl;
p->makeFriend(p);

weak_ptr<Student> wpS=p;
auto p2 = wpS.lock();
cout<<"ref count: "<< p.use_count()<<endl;
}
int main()
{
auto pS(make_shared<Student>("Ellise"));
cout<<"ref count: "<<pS.use_count()<<endl;
mystery(pS);
cout<<"ref count: "<<pS.use_count()<<endl;
return 0;
}

Step by step

Solved in 3 steps with 1 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.

Similar questions