updated docs

docs/docs/metaprogramming.xml

@@ -43,6 +43,7 @@
          <item>static_switch</item>
          <item>noncopyable</item>
          <item>enable_if</item>
+         <item>is_array2d</item>
          <item>is_graph</item>
          <item>is_rand</item>
          <item>is_matrix</item>
@@ -410,6 +411,19 @@
          
       </component>
       
+   <!-- ************************************************************************* -->
+      
+      <component>
+         <name>is_array2d</name>
+         <file>dlib/is_kind.h</file>
+         <spec_file link="true">dlib/is_kind.h</spec_file>
+         <description>
+            This is a template where is_array2d&lt;T&gt;::value == true when T
+            is an <a href="containers.html#array2d">array2d</a> object.
+         </description>
+         
+      </component>
+      
    <!-- ************************************************************************* -->
       
       <component>

docs/docs/term_index.xml

@@ -485,6 +485,7 @@
          <term link="metaprogramming.html#portability_macros" name="portability macros"/>
          <term file="metaprogramming.html" name="static_switch"/>
          <term file="metaprogramming.html" name="is_graph"/>
+         <term file="metaprogramming.html" name="is_array2d"/>
          <term file="metaprogramming.html" name="is_rand"/>
          <term file="metaprogramming.html" name="is_matrix"/>
          <term file="metaprogramming.html" name="is_std_vector"/>