Kids, don’t try this at home 🙂

class procedure DynamicArray<T>.Test();
var
  Arr : array of T;
begin
  { Fails miserably! }
end;

Error:
[DCC Fatal Error] Tests.DynamicArray.pas(772): F2084 Internal Error: URW1135

There you have it 🙂

The fix is rather simple but annoying:

Declare a new type in the class/record like this:

type
  DynamicArray<T> = class
  private
  type
    TArrayOfT = array of T;

  public
    { Lots of stuff here }
end;

And then simply make the variable Arr to be TArrayOfT:

class procedure DynamicArray<T>.Test();
var
  Arr : TArrayOfT;
begin
  { Works! }
end;

Till the next bug.