gcc/testsuite/gnat.dg/loop_unchecked_conversion.adb

   1 -- { dg-do compile }
   2 -- { dg-options "-gnatws -O" }
   3
   4 with Unchecked_Conversion;
   5
   6 package body loop_unchecked_conversion is
   7
   8    type Byte is mod 2**8;
   9
  10    type List is array (Natural range <>) of Byte;
  11
  12    subtype Integer_List is List (1 .. 4);
  13
  14    function Integer_Down is new
  15      Unchecked_Conversion (Source => Integer, Target => Integer_List);
  16
  17    type Storage (Size : Integer) is
  18       record
  19          Data : List (1 .. Size);
  20       end record;
  21
  22    type Storage_Pointer is access Storage;
  23
  24    The_Data_Storage : Storage_Pointer;
  25
  26    procedure slice is
  27    begin
  28       for I in 0 .. 1 loop
  29          The_Data_Storage.Data (I+1 .. I+4) := Integer_Down (I);
  30       end loop;
  31    end;
  32
  33 end loop_unchecked_conversion;