|  | 
        Partial specialisation of async_result
        for std::packaged_task.
      
template< typename Result, typename... Args, typename Signature> class async_result< std::packaged_task< Result(Args...)>, Signature >
| Name | Description | 
|---|---|
| The packaged task is the concrete completion handler type. | |
| The return type of the initiating function is the future obtained from the packaged task. | 
| Name | Description | 
|---|---|
| The constructor extracts the future from the packaged task. | |
| Returns the packaged task's future. | 
        Header: asio/packaged_task.hpp
      
        Convenience header: asio.hpp