+<dd><dl class="field-list simple">
+<dt class="field-odd">Parameters</dt>
+<dd class="field-odd"><ul class="simple">
+<li><p><strong>ptr</strong> -- pointer to an initialized <a class="reference internal" href="memcached_create.html#_CPPv412memcached_st" title="memcached_st"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">memcached_st</span></code></a> struct</p></li>
+<li><p><strong>group_key</strong> -- key namespace</p></li>
+<li><p><strong>group_key_length</strong> -- length of the key namespace without any terminating zero</p></li>
+<li><p><strong>key</strong> -- the key</p></li>
+<li><p><strong>key_length</strong> -- length of the key without any terminating zero</p></li>
+<li><p><strong>offset</strong> -- offset to increment/decrement</p></li>
+<li><p><strong>initial</strong> -- initial value if <a class="reference internal" href="#_CPPv439memcached_decrement_with_initial_by_keyP12memcached_stPKc6size_tPKc6size_t8uint64_t8uint64_t6time_tP8uint64_t" title="memcached_decrement_with_initial_by_key::key"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">key</span></code></a> does not exist and <a class="reference internal" href="#_CPPv439memcached_decrement_with_initial_by_keyP12memcached_stPKc6size_tPKc6size_t8uint64_t8uint64_t6time_tP8uint64_t" title="memcached_decrement_with_initial_by_key::expiration"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">expiration</span></code></a> is not <code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">MEMCACHED_EXPIRATION_NOT_ADD</span></code></p></li>
+<li><p><strong>expiration</strong> -- expiration as a unix timestamp or as relative expiration time in seconds</p></li>
+<li><p><strong>value</strong> -- the resulting value after initialization/increment/decrement</p></li>
+</ul>
+</dd>
+<dt class="field-even">Returns</dt>
+<dd class="field-even"><p><a class="reference internal" href="memcached_return_t.html#_CPPv418memcached_return_t" title="memcached_return_t"><code class="xref cpp cpp-any docutils literal notranslate"><span class="pre">memcached_return_t</span></code></a> indicating success</p>
+</dd>
+</dl>
+</dd></dl>