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1618 :: init proc with static[int] in return type

• Henry (orginal) [2015-09-07T20:44:44+02:00] view original

  I have been playing with the array type in rtarrays.nim and wanted the ArrayPartSize to be handled as a static[int] generic type parameter:

  type
    OdArray*[As: static[int], T] = object
      l: int
  
  proc initOdArray*[As: static[int], T](len: int): OdArray[As, T] =
    result.l = len
  
  var test = initOdArray[10, int](100)
  Run

  but I cannot get initOdArray to work, I get Error: type expected because the return of initOdArray is not understood as a type. Is there a way around this problem? So far the only approach I have found that works is to define a

  proc init*[As: static[int], T](a: var OdArray[As, T]; len: int)
  Run

  and pass the initOdArray as an argument after defining it but this is not the standard approach for initialization in Nim.

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• andrea (orginal) [2015-09-07T21:54:48+02:00] view original

  I think you can put the type on the left side and omit it on the right side, like

  var test: OdArray[10, int] = initOdArray(100)
  Run

  (have not checked, though)

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• Henry (orginal) [2015-09-07T22:19:30+02:00] view original

  I tried that: Error: cannot instantiate: 'As'

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• yglukhov (orginal) [2015-09-08T10:45:27+02:00] view original

  That looks like a bug to me, worth submitting. Meanwhile you can try this:

  type
    OdArray*[As: static[int], T] = object
      l: int
  
  proc initOdArray*(T: typedesc, stlen: static[int], len: int): OdArray[stlen, T] =
      result.l = len
  
  var test = initOdArray(int, 10, 100)
  Run

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• Henry (orginal) [2015-09-08T22:28:45+02:00] view original

  Thanks for the workaround, that works OK. I will also submit a bug report.

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