Mirror of forum.nim-lang.org

12739 :: ref string - Is this a bug or not allowed for a reason?

• mantielero (orginal) [2025-03-23T21:58:50+01:00] view original

  The following works:

  
  var a = "Hola"
  var b = new string
  b[] = a
  echo b[]
  Run

  But the following:

  
  type
      B = ref object
          text:ref string = new string
  
  var a = "Hola"
  var b = new B
  b.text[] = a
  Run

  fails with:

  
  nim-2.0.14/lib/system.nim(846, 8) Error: string literal must be of some string type
  Run

  Is this a bug or is there anything I can do to fix it?

---

• mantielero (orginal) [2025-03-23T22:14:24+01:00] view original

  This seems to work:

  
  type
    B = ref object
      text:ref string #= new string
  
  proc newStringRef(s = ""): ref string =
    new(result)
    result[] = s
  
  var a = newStringRef("Hola")
  var b = new B
  b.text = a
  echo b.text[]
  Run

  https://gist.github.com/Varriount/c3ba438533497bc636da

---

• Araq (orginal) [2025-03-23T22:36:52+01:00] view original

  If you need a ref string you're already doing it wrong. Use string and move it around or use an ID mechanism and a table[Key, string] or a BiTable (which is sadly still not in the stdlib).

---

• mantielero (orginal) [2025-03-24T21:50:27+01:00] view original

  Understood. Thank you

---