std::packaged_task::reset(3)

💅 std::packaged_task::reset 💅

okay so bestie, this page is from the C++ Standard Libary manual — yes, that’s literally the spelling on the page 💀 — and it’s all about std::packaged_task::reset.

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✨ NAME ✨

std::packaged_task::reset — std::packaged_task::reset

it’s giving “same name, same energy, one tiny function” 🎀

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🌸 Synopsis 🌸

void reset();  (since C++11)

so this baby has been around since C++11, periodt ✨

Resets the state abandoning the results of previous executions. New shared state is constructed.

Equivalent to *this = packaged_task(std::move(f)), where f is the stored task.

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🎀 Parameters 🎀

(none) — literally no parameters, bestie 🫶

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🦋 Return value 🦋

(none) — nope, nothing comes back 💖

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💀 Exceptions 💀

• std::future_error if *this has no shared state. The error condition is set to no_state.
• std::bad_alloc if there was not enough memory for a new shared state.
• Any exception thrown by the move constructor of the new packaged_task.

like, if any of these pop off, it’s a whole thing 😭 no cap.

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🍓 Example 🍓

// Run this code

#include <cmath>
#include <future>
#include <iostream>
#include <thread>

int main()
{
    std::packaged_task<int(int,int)> task([](int a, int b)
    {
        return std::pow(a, b);
    });
    std::future<int> result = task.get_future();
    task(2, 9);
    std::cout << "2^9 = " << result.get() << '\n';

    task.reset();
    result = task.get_future();
    std::thread task_td(std::move(task), 2, 10);
    task_td.join();
    std::cout << "2^10 = " << result.get() << '\n';
}

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⭐ Output ⭐

2^9 = 512
2^10 = 1024

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byeee 🫶 — source: http://cppreference.com, version/date: 2024.06.10, page: std::packaged_task::reset(3) 💖