message: Add missing policy getter to task_queue
diff: @@ -97,6 +97,11 @@ public:
  // -- observers -------------------------------------------------------------
  + /// Returns the policy object.
  + policy_type& policy() noexcept {
  + return policy_;
  + }
  +
  /// Returns the policy object.
  const policy_type& policy() const noexcept {
  return policy_;
  