SNMP++v3.x is a C++ API which supports SNMP v1, v2c, and v3.

SNMP++v3.x is based on SNMP++v2.8 from HP* and extends it by support
for SNMPv3 and a couple of bug fixes.

The v3 support to SNMP++ and AGENT++ is provided by courtesy of
Jochen Katz (katz07@agentpp.com).

SNMP++v3.x extends the original SNMP++v2.8 by the following:
# SNMPv3 including User Security Model (USM) with:
# MD5 and SHA authentication
# DES and IDEA privacy
# Thread-safety
# Bug-fixes

WWW: http://www.agentpp.com/snmp_pp3_x/snmp_pp3_x.html for further details.