I'm not very good at D, but if you are referring to row polymorphic records, Haskell can do that too (e.g. https://github.com/nikita-volkov/record-preprocessor/

I'm not very good at D, but if you are referring to row polymorphic records, Haskell can do that too (e.g. https://github.com/nikita-volkov/record-preprocessor/blob/master/demo/Main.hs https://github.com/nikita-volkov/record-preprocessor/blob/ma...)