Log message:
Not working-in-progress here anymore.

Log message:
Import ossp-ex-1.0.6 as wip/ossp-ex.

OSSP ex is a small ISO-C++ style exception handling library for use in the ISO-C
language. It allows you to use the paradigm of throwing and catching exceptions
in order to reduce the amount of error handling code without making your program
less robust.

This is achieved by directly transferring exceptional return codes (and the
program control flow) from the location where the exception is raised (throw
point) to the location where it is handled (catch point) -- usually from a
deeply nested sub-routine to a parent routine. All intermediate routines no
longer have to make sure that the exceptional return codes from sub-routines are
correctly passed back to the parent.

The OSSP ex facility also provides advanced exception handling features like
shielded and deferred exceptions. Additionally, OSSP ex allows you to choose the
used underlying machine context switching facility and optionally support multi-
threading environments by allowing you to store the exception catching stack in
a thread-safe way.