When I follow all the instructions (including apple\'s video) to drag text to create a code snippet in xcode, I get a different system behavior: all I see is the selection i
On High Sierra 10.13.3 and XCode 9 I faced the same problem. The decision that works for me is selecting code on a blank space before the first symbol and then dragging it to the snippets library.
Important: you need to drag only from the blank space (look at the screenshot below). Otherwise you will reselect your code again.
The cursor changes only when you start dragging, so don't be confused and don't wait until it changes.