Added build.type switch to HelloWorld example

Avoiding the build of the experimental cpp HelloWorld example
in stable builds

Change-Id: I4d4f9c0ae353bbe140aed0c7c4dd2479e6b911cc

git-svn-id: https://svn.apache.org/repos/asf/incubator/etch/trunk@1368972 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/examples/helloworld/build.xml b/examples/helloworld/build.xml
index e12c21d..1d09b7e 100644
--- a/examples/helloworld/build.xml
+++ b/examples/helloworld/build.xml
@@ -46,7 +46,7 @@
         <build_component dir="java" />
         <build_component dir="csharp" />
         <build_component dir="c" />
-        <build_component dir="cpp" />
+        <antcall target="component-bindings-experimental" />
     </target>
 
     <target name="do-postbuild">
@@ -54,6 +54,18 @@
 
     <target name="do-help">
     </target>
+    
+    <!-- Experimental Binding examples -->
+    <target name="component-bindings-experimental" depends="component-bindings-experimental-if, component-bindings-experimental-then">
+    </target>
+    <target name="component-bindings-experimental-if">
+        <condition property="is-build-type-experimental">
+            <equals arg1="${build.type}" arg2="experimental" />
+        </condition>
+    </target>
+    <target name="component-bindings-experimental-then" if="is-build-type-experimental">
+        <build_component dir="cpp" />
+    </target>
 
 </project>