print mutex for printing for error handling

Author: MaartenMarsman

src/print_mutex.h

@@ -9,3 +9,13 @@ inline tbb::mutex& get_print_mutex() {
 }
 
 #endif // PRINT_MUTEX_H
+
+// Add this header to the parallel code you wish to print from
+// + the below code to print in parallel code:
+//
+// {
+//   tbb::mutex::scoped_lock lock(get_print_mutex());
+//   std::cout
+//   << "print "
+//   << std::endl;
+// }