====== zapp_GetUID ======

===== Description =====

Get a unique identifier (UID) from the application as a signed integer.

===== Files =====

^ Declaration | ''helper/zApp.h'' |
^ Implementation | ''helper/zApp.cpp'' |

===== Function prototype =====

<code="C++">
long zapp_GetUID();
</code>

===== Return value =====

-1 if an error occurs, and otherwise a signed integer of value 0 or greater. 

===== Comments =====

==== Uniqueness and wrap-around ====

Each call to ''zapp_GetUID'' increments an internal counter in L3DT, such that subsequent calls are guaranteed to receive a unique value that is greater than all previous values, up until wraparound occurs at circa 2 billion.