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9316 :: How to make property nil?

• carcinocron (orginal) [2022-07-22T18:01:15+02:00] view original

  Here is my full code.

  type Foo = object
    prop: uint8
  
  let a = Foo(prop: 4)
  a.prop = nil
  
  let b = Foo(prop: nil)
  b.prop = 5
  Run

  I can't figure out how to make this value null. Most things I try will create wrapper objects like { prop: [null, 0] } or won't compile.

  Here are some things I guessed would work but don't compile:

  type Foo = object
    prop: uint8?
  
  type Foo = object
    prop: uint8 | Nil
  
  type Foo = object
    prop: uint8 | nil
  Run

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• PMunch (orginal) [2022-07-22T19:11:39+02:00] view original

  Nil is a special value for pointer types (ref, ptr, etc) and doesn't apply to value types like an integer. What you want to do is achieved through the options module.

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