Surprisingly a lot, actually. Slate recently posted a video essay that reveals the peculiar and perfect connections between two sub-genres of films that couldn't seem to be less related: film noir and stoner comedies. If you're a complete film theory/history nerd like yours truly, you're going to want to learn all about "Slacker Noir".
Now, it's important to know about each of these sub-genres to really get a handle on what the video is talking about. First, film noir. So much study has been done on this type of film, specifically by French critics Etienne Chaumeton and Raymond Borde, who characterized these stark, black and white melodramas as "oneiric, strange, erotic, ambivalent, and cruel." Though these five attributes don't completely define or even relate to every film noir, they do speak to the lion's share of them, like The Maltese Falcon, The Big Sleep, Double Indemnity, and Mildred Pierce.