Proposed resolution:

Resolved by adoption of P0600 in Albuquerque

[ 2017-03-04, Kona ]

This should be handled by Nico's paper P0600.

[ 2017-01-27 Telecon ]

Priority 2; Nico to provide wording.

Because the destructor of the std::future returned from the std::async blocks until the asynchronous operation completes, discarding the std::async return value leads to the synchronous code execution, which is pointless. For example, in the following code

void task1();
void task2();

void foo()
{
  std::async(std::launch::async,  task1),
  std::async(std::launch::async,  task2);
}

void bar()
{
  std::async(std::launch::async,  task1);
  std::async(std::launch::async,  task2);
}

task1 and task2 will be concurrently executed in the function 'foo', but sequentially in the function 'bar'.