wk07_STL_2


Based on your request and the provided search results, I'll create a C++ program that incorporates std::list, std::tuple, std::function, and std::bind to simulate a task queue for different physical models and implement a callback mechanism. Here's the implementation:

Resources (C++ Tutorial)

algorithm, auto, command_line_arguments, exception, iostream, namespace, range-based, sstream, std::cin, std::cout, std::cerr, std::exception, stdexcept, throw, vector

#include <iostream>
#include <list>
#include <string>
#include <functional>
#include <tuple>
#include <thread>
#include <chrono>

// Result structure representing simulation results
using SimulationResult = std::tuple<double, double, double>; // time step, energy, entropy

// Task structure representing a simulation task
struct Task {
    std::string name;
    int duration;  // Duration in seconds
    std::function<SimulationResult()> simulationFunc;

    Task(const std::string& n, int d, std::function<SimulationResult()> func) 
        : name(n), duration(d), simulationFunc(func) {}
};

// Observer class to be notified of simulation progress
class SimulationObserver {
public:
    virtual void update(const std::string& taskName, const SimulationResult& result) = 0;
};

// Concrete observer for visualization
class VisualizationTool : public SimulationObserver {
public:
    void update(const std::string& taskName, const SimulationResult& result) override {
        std::cout << "Visualization update for " << taskName << ": "
                  << "Time step: " << std::get<0>(result)
                  << ", Energy: " << std::get<1>(result)
                  << ", Entropy: " << std::get<2>(result) << std::endl;
    }
};

// Simulation class managing task queue
class Simulation {
public:
    void addTask(const Task& task) {
        tasks.push_back(task);
    }

    void addObserver(SimulationObserver* observer) {
        observers.push_back(observer);
    }

    // Run all tasks in the order they were added
    void runTasks() {
        for (const auto& task : tasks) {
            std::cout << "Running task: " << task.name << " for " << task.duration << " seconds\n";
            std::this_thread::sleep_for(std::chrono::seconds(task.duration));

            SimulationResult result = task.simulationFunc();
            notifyObservers(task.name, result);
        }
    }

private:
    std::list<Task> tasks;  // Use std::list to manage task queue
    std::list<SimulationObserver*> observers;

    void notifyObservers(const std::string& taskName, const SimulationResult& result) {
        for (auto observer : observers) {
            observer->update(taskName, result);
        }
    }
};

// Example simulation functions
SimulationResult simulateModel1() {
    return std::make_tuple(0.1, 100.0, 0.5);
}

SimulationResult simulateModel2() {
    return std::make_tuple(0.2, 200.0, 1.0);
}

int main() {
    Simulation sim;
    VisualizationTool vizTool;

    sim.addObserver(&vizTool);

    // Using std::bind to create tasks with different simulation functions
    sim.addTask(Task("Model 1", 2, std::bind(simulateModel1)));
    sim.addTask(Task("Model 2", 3, std::bind(simulateModel2)));

    std::cout << "Starting simulation...\n";
    sim.runTasks();
    std::cout << "Simulation finished.\n";
    return 0;
}

This program demonstrates the use of the requested C++ features:

  1. std::list: Used to manage the task queue in the Simulation class and to store observers.

  2. std::tuple: Used to represent SimulationResult, storing multiple properties (time step, energy, and entropy) in a single object.

  3. std::function: Used in the Task struct to store the simulation function for each task.

  4. std::bind: Used in the main function to create tasks with different simulation functions.

  5. Callbacks: Implemented through the SimulationObserver interface and the VisualizationTool class, which are notified of simulation progress.

The program simulates a task queue for different physical models, runs each task, and updates observers (in this case, a visualization tool) with the results of each simulation step. This structure provides a flexible framework for running multiple simulations and handling their results, which is common in scientific computing and numerical simulations.

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