// This example demonstrates how to attach data to a task and run
// the task iteratively with changing data.

#include 

int main(){

  tf::Executor executor;
  tf::Taskflow taskflow("attach data to a task");

  int data;

  // create a task and attach it the data
  auto A = taskflow.placeholder();
  A.data(&data).work([A](){
    auto d = *static_cast(A.data());
    std::cout