• Dart

final k = m.keys;

• Go

k := maps.Keys(m)

• Go

k := make([]K, 0, len(m))
for key := range m {
	k = append(k, key)
}

• Java

List<K> k = new ArrayList<>(m.keySet());

• Java

List<K> k = copyOf(m.keySet());

• Pascal

type
  TList = specialize TFPGList<TKey>;
  TMap = specialize TFPGMap<TKey, TData>;

var
  m: TMap;
  k: TList;

begin
  ....
  k := TList.Create;
  for idx := 0 to m.Count-1 do k.Add(m.Keys[idx]);
  .....
  k.Free;
  ....

• Perl

@k = keys %m;

• Python

k = m.keys()

• Python

k = [*m.keys()]

• Python

k = list(m.keys())

• Ruby

k = m.keys

• Rust

m.keys().collect::<Vec<_>>()