Some reformatting and changed packaged_task to function

include/ThreadPool.h

@@ -14,14 +14,15 @@ it. Using this library is your own responsibility
 #ifndef THREADPOOL_H
 #define THREADPOOL_H
 
+#include <condition_variable>
 #include <deque>
 #include <functional>
 #include <mutex>
 #include <thread>
 #include <vector>
-#include <condition_variable>
 
-class ThreadPool {
+class ThreadPool
+{
     long                              numOfThreads;
     std::deque<std::function<void()>> _tasks;
     std::mutex                        _queueLock;
@@ -41,12 +42,12 @@ public:
     inline ~ThreadPool();
     inline void push(const std::function<void()>& task);
     inline void push(std::function<void()>&& task);
-  inline void
+    inline void start(const long NumOfThreads = std::thread::hardware_concurrency());
-  start(const long NumOfThreads = std::thread::hardware_concurrency());
     inline void finish();
 };
 
-void ThreadPool::thread_worker() {
+void ThreadPool::thread_worker()
+{
     while (true) {
         std::unique_lock<decltype(_queueLock)> lg(_queueLock);
         while (_tasks.empty() && !conclude_work) {
@@ -67,7 +68,8 @@ void ThreadPool::thread_worker() {
     }
 }
 
-void ThreadPool::join_all() {
+void ThreadPool::join_all()
+{
     for (long i = 0; i < static_cast<long>(_threads.size()); i++) {
         if (_threads[i].joinable())
             _threads[i].join();
@@ -78,19 +80,22 @@ ThreadPool::ThreadPool() {}
 
 ThreadPool::~ThreadPool() { this->finish(); }
 
-void ThreadPool::push(const std::function<void()> &task) {
+void ThreadPool::push(const std::function<void()>& task)
+{
     std::unique_lock<decltype(_queueLock)> lg(_queueLock);
     _tasks.push_back(task);
     _queueCond.notify_one();
 }
 
-void ThreadPool::push(std::function<void ()>&& task) {
+void ThreadPool::push(std::function<void()>&& task)
+{
     std::unique_lock<decltype(_queueLock)> lg(_queueLock);
     _tasks.push_back(std::move(task));
     _queueCond.notify_one();
 }
 
-void ThreadPool::start(const long NumOfThreads) {
+void ThreadPool::start(const long NumOfThreads)
+{
     if (!started_already)
         started_already = true;
     else
@@ -98,13 +103,13 @@ void ThreadPool::start(const long NumOfThreads) {
     numOfThreads = NumOfThreads;
     _threads.reserve(numOfThreads);
     for (long i = 0; i < numOfThreads; i++) {
-    _threads.push_back(
+        _threads.push_back(std::thread(std::bind(&ThreadPool::thread_worker, this)));
-        std::thread(std::bind(&ThreadPool::thread_worker, this)));
         num_of_threads_running++;
     }
 }
 
-void ThreadPool::finish() {
+void ThreadPool::finish()
+{
     std::unique_lock<decltype(_queueLock)> lg(_queueLock);
     conclude_work = true;
     _queueCond.notify_all();

main.cpp

@@ -1,8 +1,10 @@
+#include <future>
 #include <iostream>
 
 #include "include/ThreadPool.h"
 
-void SumZeroToNumber(long &num) {
+void SumZeroToNumber(long& num)
+{
     long val = 0;
     for (long i = 0; i <= static_cast<long>(num); i++) {
         val += i;
@@ -10,7 +12,8 @@ void SumZeroToNumber(long &num) {
     num = val;
 }
 
-int main() {
+int main()
+{
     for (int tries = 0; tries < 10; tries++) {
         std::cout << "Try number: " << tries + 1 << "... ";
 
@@ -29,12 +32,15 @@ int main() {
                 // unchanged
                 pool.push(std::bind(SumZeroToNumber, std::ref(numsResults[i])));
             }
+            long                  num = 10;
+            std::function<void()> task(std::bind(SumZeroToNumber, std::ref(num)));
+            pool.push(std::move(task));
+
             //    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
             pool.finish();
         } catch (std::exception& ex) {
-      std::cout
+            std::cout << "An exception was thrown while processing data. Exception says: " << ex.what()
-          << "An exception was thrown while processing data. Exception says: "
+                      << std::endl;
-          << ex.what() << std::endl;
             std::exit(1);
         }
         //  test results sequentially
@@ -42,8 +48,8 @@ int main() {
             SumZeroToNumber(numsSequentialResults[i]);
             if (numsSequentialResults[i] != numsResults[i]) {
                 std::cout << "failed." << std::endl;
-        std::cout << "Comparing " << numsSequentialResults[i] << " with "
+                std::cout << "Comparing " << numsSequentialResults[i] << " with " << numsResults[i]
-                  << numsResults[i] << " failed." << std::endl;
+                          << " failed." << std::endl;
                 throw std::runtime_error("Results didn't match!");
             }
         }