Scenario: I control a Wharf Infiltrator and Platinum Angel. I have a creature card in hand and no cards in my library. I attack with Wharf Infiltrator. It is not blocked and combat damage is not prevented.

Question: If I choose to draw a card, do I get to discard my creature card even though there are no cards to draw from my library?

I'm leaning towards a no (55% sure it's correct) but want to be sure.

120.3. If there are no cards in a player's library and an effect offers that player the choice to draw a card, that player can choose to do so. However, if an effect says that a player can't draw cards and another effect offers that player the choice to draw a card, that player can't choose to do so.

117.12. Some spells, activated abilities, and triggered abilities read, "[Do something]. If [a player] [does or doesn't], [effect]." or "[A player] may [do something]. If [that player] [does or doesn't], [effect]." The action [do something] is a cost, paid when the spell or ability resolves. The "If [a player] [does or doesn't]" clause checks whether the player chose to pay an optional cost or started to pay a mandatory cost, regardless of what events actually occurred.