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Comment by brightprogramer | Hacker News Reader

Yea the FMT trick uses VA_OPT. I consider myself a noob with C official specification, so you're probably right about that.

I do kinda like how foreach is implemented right now. This allows me to perform some strict checking for easy loop iteration based bugs and also it kinda looks cool.

This is the first time I came across typeof_unqual. I'll look into it, thanks .

I spent a lot of time making this work across all three compilers (especially MSVC). I'm glad MSVC has VA_OPT support.

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> I do kinda like how foreach is implemented right now. This allows me to perform some strict checking for easy loop iteration based bugs and also it kinda looks cool.

Yes but the body in the parameters really is a show stopper. What if the body has a unprotected comma? Like

  VecForeach(&v, e, {
    int x, y;
    ...
  });

Better to expand the macro into one or two "for" and let the body follow. For example:

  #define VecForeachIdx(v, var, idx)\
    for (size idx=0,_d=1; ValidateVec(v),_d; _d--)\
      for (VEC_DATATYPE(v) var={}; idx<(v)->length && (var=VecAt(v,idx),1); idx++)

Please note that I haven't tested it.

That sounds like a better idea. I'll test it. Debugging with my existing macros is a PITA, but if your suggestion works then it'll work well with debuggers as well! Thanks :)

How would you implement 'var = ...' while respecting that 'VecAt(...)' could return 0? I am currently working on a similar problem and can't seem do seem figure out how to handle these for-loops and setting the iterator properly.

The ",1" ignores var and keeps 1.

I just tested this, and it works flawlessly! This is amazing! Thanks for the suggestion.

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