Can namerefs (declare -n) be used with arrays in bash? What does the documentation mean when it says declare -n cannot be applied to arrays?

Question

In another question to stackoverflow, I asked how to pass array to a function. An answer recommended me a previous answers. One answer suggests that declare with -n option, referencing, is useful to pass array to an function, like following,

declare -a array=( 1 2 )

function array_pass_by_reference_func() {
  local -n aug=${1:-dummy}
  echo "pass by reference : array[0] = ${aug[0]}"
  echo "pass by reference : array[1] = ${aug[1]}"
  echo "pass by reference : array = ${aug[@]}"
}

# execute an example function above
array_pass_by_reference_func "array"

# output
pass by reference : array[0] = 1
pass by reference : array[1] = 2
pass by reference : array = 1 2

It looks working well. My question here is about an instruction of declare -n in bash manual,

The -n attribute cannot be applied to array variables.

I would like to confirm that can I pass array to a function with declare -n option? My original question is marked as duplicated and the previous question is too old to ask this question. So please let me ask it here. Thank you very much.

Answer 1

Further down on the man page, under the PARAMETERS heading, it also says:

However, nameref variables can reference array variables and subscripted array variables.

In other words:

• You can't declare a nameref variable itself as an array (declare -a -n foo=... will result in a syntax error).
• But a nameref variable can reference an array.

Therefore, your approach should be safe.