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6315 :: Reference to sequence

• dataPulverizer (orginal) [2020-05-10T20:44:29+02:00] view original

  How do you create a reference to a sequence? I can see how you create a pointer to a sequence:

  
  var x: seq[float64] = @[1.0,  2, 3, 4, 5];
  var y = x.addr;
  Run

  But have no idea how to create ref seq[float64], or is it only possible to create a ptr seq[float] while the ref keyword is only really used when defining objects?

  Thanks in advance.

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• dataPulverizer (orginal) [2020-05-10T21:21:21+02:00] view original

  Many thanks, dereferencing ref s is done using x[] as in your answer.

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• dataPulverizer (orginal) [2020-05-10T21:51:03+02:00] view original

  Sorry quick extension to that question, if I have a variable that is a seq[T], how do I assign it to a new variable that is a ref seq[T] ... or otherwise how do I transform a variable that is a seq[T] to a ref seq[T] ?

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• mratsim (orginal) [2020-05-10T23:41:28+02:00] view original

  @b3liever post shows you how to dereference a ref, not a seq

  i.e. if it wasn't clear

  proc assignToRef[T](x: T): ref T =
    new result # allocate the ref object, any type works
    result[] = x # assign it x
  
  let y = assignToRef(@[1.0,  2, 3, 4, 5])
  Run

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• dataPulverizer (orginal) [2020-05-11T00:44:44+02:00] view original

  Thanks, I don't know why I didn't think of that. I thought there would be a builtin for transforming something to ref, but this is fine.

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• Stefan_Salewski (orginal) [2020-05-11T06:51:04+02:00] view original

  would be a builtin for transforming something to ref,

  Have you been able to read

  http://ssalewski.de/nimprogramming.html#_references_and_pointers

  If so, what may I improve?

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