c++11 async continuations or attempt at .then() semantics

Question

The code below is based on Herb Sutter\'s ideas of an implementation of a .then() type continuation.

  template
auto then(F         


        

Answer 1

Here is the solution, tested with g++ 4.8 and clang++ 3.2:

template
auto then(F&& f, W w) -> std::future
{
  cout<<"In thread id = "< result=std::async([]{ return 12;});
  auto f = then(std::move(result), [](int r) {
    cout<<"[after] thread id = "<