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Lære Methods of a Unique Pointer | Unique Pointers
C++ Smart Pointers

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Methods of a Unique Pointer

Since std::unique_ptr is a class template it provides various methods to manage itself safely.

cpp

main

copy
#include <iostream>
#include <memory>

struct Sample {
Sample(int v)
: value(v) {}
int value;
void GetValue() { std::cout << "Value: " << value << std::endl; }
};

int main()
{
// Creating a `unique_ptr`
std::unique_ptr<Sample> p_first = std::make_unique<Sample>(10);

// Using `get()` to retrieve the raw pointer
Sample* p_raw = p_first.get();
std::cout << "Raw pointer value: " << p_raw->value << std::endl;

// Using `release()` to transfer ownership
Sample* p_released = p_first.release();
if (!p_first)
std::cout << "p_first is now empty after release.\n";

// Manually delete the released pointer to avoid memory leak
delete p_released;

// Resetting the `unique_ptr`
p_first.reset(new Sample(20));
p_first->GetValue();

// Using `swap()` with another `unique_ptr`
std::unique_ptr<Sample> p_second = std::make_unique<Sample>(30);
p_first.swap(p_second);
p_first->GetValue(); // Now `p_first` owns `p_second` object
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#include <iostream> #include <memory> struct Sample { Sample(int v) : value(v) {} int value; void GetValue() { std::cout << "Value: " << value << std::endl; } }; int main() { // Creating a `unique_ptr` std::unique_ptr<Sample> p_first = std::make_unique<Sample>(10); // Using `get()` to retrieve the raw pointer Sample* p_raw = p_first.get(); std::cout << "Raw pointer value: " << p_raw->value << std::endl; // Using `release()` to transfer ownership Sample* p_released = p_first.release(); if (!p_first) std::cout << "p_first is now empty after release.\n"; // Manually delete the released pointer to avoid memory leak delete p_released; // Resetting the `unique_ptr` p_first.reset(new Sample(20)); p_first->GetValue(); // Using `swap()` with another `unique_ptr` std::unique_ptr<Sample> p_second = std::make_unique<Sample>(30); p_first.swap(p_second); p_first->GetValue(); // Now `p_first` owns `p_second` object // Dereferencing the pointer std::cout << "Dereferencing p_first: " << (*p_first).value << std::endl; // Accessing members using `->` operator p_first->GetValue(); }
question mark

What does the reset() function do when called without a parameter?

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