gcc/testsuite/gnat.dg/pointer_conversion.adb

   1 -- { dg-do run }
   2 -- { dg-options "-O2" }
   3
   4 with Unchecked_Conversion;
   5
   6 procedure pointer_conversion is
   7
   8    type int1 is new integer;
   9    type int2 is new integer;
  10    type a1 is access int1;
  11    type a2 is access int2;
  12
  13    function to_a2 is new Unchecked_Conversion (a1, a2);
  14
  15    v1 : a1 := new int1;
  16    v2 : a2 := to_a2 (v1);
  17
  18 begin
  19    v1.all := 1;
  20    v2.all := 0;
  21
  22    if v1.all /= 0 then
  23       raise Program_Error;
  24    end if;
  25 end;