In XGC Ada, many of the Ada 95 predefined packages are unavailable. In most cases this is because the standard package uses some language feature that is the subject of a restriction. However some packages are only rejected for a trivial use of a restricted features, and can be simply modified to be useful to the XGC programmer. This appendix described the package that have been made available in this way, also with several others that are no taken from the Ada Language Reference Manual, but which are nevertheless important.
At the time of writing, predefined packages exist as follows. More packages are planned and these will be documented as necessary.
The following implementation-defined library package exists:
package XGC is pragma Pure (XGC); end XGC;
This is the parent package for all the implementation-defined packages. It is usually included implicitly, and includes no useful declarations. In the standard mode, it is illegal to compile a child of package XGC.