Augmented assignment (+=) expression on a read-only Collection temporarily allocates a new collection, which may hurt performance.

Change type to mutable quick-fix can be used to amend the code automatically.

Example:

  fun test() {
      var list = listOf(0)
      list += 42 // A new list is allocated here, equivalent to list = list + 42
  }

After the quick-fix is applied:

  fun test() {
      val list = mutableListOf(0)
      list += 42
  }