var
  s : String; // long
  p : PChar;
begin
  // Typecast as pchar 
  // Typecasting a string to a PChar returns the address of the first char
  // or if the string was empty it returns the address of a null. 
  // Result p is guaranteed to be non-nil!
  p := PChar(s);
  
  // Take address of the first character
  // this forces a call to UniqueString() to ensure that the pchar returned
  // points to a unique string only referenced by s and not by another string:
  p:=@s[1];


  // Typecast the string to an untyped pointer
  // The simplest and fastest solution; no hidden function call is generated.
  p := pointer(s);
end.