1.2.6 $BITPACKING : Enable bitsize packing

The $BITPACKING directive tells the compiler whether it should use bitpacking or not when it encounters the packed keyword for a structured type. The possible values are ON and OFF. If ON, then the compiler will bitpack structures when it encounters the Packed keyword.

In the following example, the TMyRecord record will be bitpacked:

{$BITPACKING ON}
Type
  TMyRecord = packed record
    B1,B2,B3,B4 : Boolean;
  end;

Note that: