D implementation of algebraic type is in the library. https://dlang.org/phobos/std_variant.html#.Algebraic https://dlang.org/phobos/std_variant.html#.Algebraic

D implementation of algebraic type is in the library. https://dlang.org/phobos/std_variant.html#.Algebraic https://dlang.org/phobos/std_variant.html#.Algebraic I have not utilized tagged unions outside this type so I'm not one to comment on any deficiency.