Found a monad
@jsgf
toilet paper roll
condom
ketchup packet
COVID test
Hypodermic needle
Hot chip
Philly cheese steak
Drinking straw
N95 mask
The easiest one to understand is Option. This is Option<TP>. Until you remove the wrapper, you don’t know if it’s Some<TP> or None.
Other languages/libraries have Left/Right, and Rust has Result. There’s other things I’m sure but I am not a math nerd so don’t know the specifics about what qualifies. (Is Box<Foo> a Monad in Rust?)