Can you please point out what about Buckaroo's (i.e., the author's) solution is wrong? I take it, his version of Either is copied from the neither project [1],

Can you please point out what about Buckaroo's (i.e., the author's) solution is wrong? I take it, his version of Either is copied from the neither project [1], so the destructor of the union is: ~Either() { if(isLeft) { leftValue.~L(); } else { rightValue.~R(); } } Which does explicitly call the destructors. (Obviously, if you only were referring to his eight-line toy version of Either for the blog, please forget my comment.) [EDIT: re-reading your comment once more, I see you did indeed mean the blog implementation; please ignore this comment.] [EDIT2: BTW, it seems the author is "affiliated" with that LoopPerfect/neither implementation.] [1] https://github.com/LoopPerfect/neither/blob/master/neither/include/either.hpp https://github.com/LoopPerfect/neither/blob/master/neither/i...