``` type foo = /** Foo variant */ | Foo type polyFoo = [ /** Foo polymorphic variant */ | #Foo ] ``` Playground: https://rescript-lang.org/try/?version=v12.0.0-rc.3&module=esmodule&code=C4TwDgpgBAZg9nKBeAUFKB6AVFqAxBKANwEMAnASxIDtgosM0oAffBFD0SKMOAGxAFESKAG0m2XEJ78QAWzhkwACwoBjYuSq16jdKwDEQlAF0OQA