std::swap(std::shared_ptr)(3)

💖 NAME 💖

std::swap(std::shared_ptr) - std::swap(std::shared_ptr). That's the name, bestie. This is page std::swap(std::shared_ptr)(3) from the C++ Standard Libary manual, and it's here to make your shared pointers trade places. 💅

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✨ Synopsis ✨

Okay so this one is defined in header <memory>:

template< class T >
void swap( std::shared_ptr<T>& lhs, std::shared_ptr<T>& rhs )
(since C++11)
noexcept;

It specializes the std::swap algorithm for std::shared_ptr. It swaps the contents of lhs and rhs. Then it calls lhs.swap(rhs). That's the whole lore, no cap. 🦋

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🌸 Parameters 🌸

• lhs, rhs — smart pointers whose contents to swap. They're the two icons trading places, fr fr. 💖

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🎀 Return value 🎀

(none) — literally no return value, bestie. It just does the swap and leaves. 🫶

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🦋 Complexity 🦋

Constant. That's the whole note — constant. ⭐

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🔥 Example 🔥

Run this code, bestie:

// Run this code

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

struct Foo {
    Foo(int _val) : val(_val) { std::cout << "Foo...\n"; }
    ~Foo() { std::cout << "~Foo...\n"; }
    std::string print() { return std::to_string(val); }
    int val;
};

int main()
{
    std::shared_ptr<Foo> p1 = std::make_shared<Foo>(100);
    std::shared_ptr<Foo> p2 = std::make_shared<Foo>(200);
    auto print = [&]() {
        std::cout << " p1=" << (p1 ? p1->print() : "nullptr");
        std::cout << " p2=" << (p2 ? p2->print() : "nullptr") << '\n';
    };
    print();

    std::swap(p1, p2);
    print();

    p1.reset();
    print();

    std::swap(p1, p2);
    print();
}

☕ Output 🍓

Foo...
Foo...
 p1=100 p2=200
 p1=200 p2=100
~Foo...
 p1=nullptr p2=100
 p1=100 p2=nullptr
~Foo...

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👀 See also 👀

• swap — swaps the values of two objects (function template). 👑
• swap — swaps the contents (public member function). 🫶

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Source/version: http://cppreference.com; date: 2024.06.10; page: std::swap(std::shared_ptr)(3). Bye bestie, periodt. 💖