I don't know what this feature is called, so I'm having a hard time searching for a solution.

When I type two dashes, --, I want Word to convert it to one long dash. Usually, I copy/paste a long dash from another doc and use Replace. But I'd like to do it the right way.

Under: File > Options > Proofing > AutoCorrect Options, even though it's set to auto format a variety of keystrokes, it's still not doing the two dashes. Smart quotes work, fractions and ordinals automatically reformat on the screen. Why does it not recognize the dash,dash?