Async Call

gistfile1.cpp

#define ASYNC_CALL(func, callback, ...)                           \
  FSReqWrap* req_wrap = new FSReqWrap();                          \
  int r = uv_fs_##func(uv_default_loop(), &req_wrap->req_,        \
      __VA_ARGS__, After);                                        \
  assert(r == 0);                                                 \
  req_wrap->object_->Set(oncomplete_sym, callback);               \
  req_wrap->Dispatched();                                         \
  return scope.Close(req_wrap->object_);