Worst ideas/features in programming languages?

[sighoya]

On Monday, 11 October 2021 at 15:59:10 UTC, Atila Neves wrote:
> * Worst features implemented in a non-toy language

  - C Preprocessor
  - C Macros
  - Error handling through return codes
  - Languages with undecidable grammar

> * Worst features (in your opinion) in D

  - I need more time for this to find ones, but mostly it is the 
half backedness of features

> * Features you'd like to see in D
  - structs implementing interfaces
  - autoboxing structs to interfaces
  - faster, easier and more powerful CTFE, I think this will come 
with newCTFE
  - runtime templates/runtime reflection (not as default, but as 
an option)

I'm unsure about type classes/protocols/concepts/traits, they 
are, theoretically, clearly superior to OOP, but as we already 
have classes & interfaces in D, they would be too overlapping, I 
think.