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Actually (insert nerd emoji) this is a direct descendant from tagged union type, which existed in ALGLO 68, an imperative language.

Java's checked exception is just an (very anti-ergonomic) implementation of tagged union type.

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OK, but it wasn't until functional programming came along that tagged unions were recognized as a natural way to implement sum types, which is how they are used in modern programming. The old idea of a "variant" has pretty much faded away.

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