# C++ unique_ptr

**[unique_ptr](https://en.cppreference.com/w/cpp/memory/unique_ptr)** is an exclusive-ownership smart pointer that automatically deletes its managed object when destroyed. Only one `unique_ptr` can own an object at a time; ownership is transferred via move semantics, never copied.

Use `unique_ptr` by default for dynamic memory to prevent leaks and clarify ownership.

## Example

This example demonstrates exclusive ownership transfer and automatic cleanup with unique_ptr.

```cpp
// compile: g++ -o unique unique.cpp
// run: ./unique
// description: unique_ptr transfers ownership and auto-deletes on destruction

#include <iostream>
#include <memory>

class Resource {
public:
    Resource() { std::cout << "Resource allocated\n"; }
    ~Resource() { std::cout << "Resource freed\n"; }
    void use() { std::cout << "Using resource\n"; }
};

int main() {
    {
        std::unique_ptr<Resource> r1 = std::make_unique<Resource>();
        r1->use();
        
        std::unique_ptr<Resource> r2 = std::move(r1);  // ownership transferred
        r2->use();
    }  // r2 destroyed here, resource freed
    
    return 0;
}
```