update to new build system

examples/optional_serialization.cxx

@@ -0,0 +1,46 @@
+/*! @file
+
+    @id $Id$
+*/
+//       1         2         3         4         5         6         7         8
+// 45678901234567890123456789012345678901234567890123456789012345678901234567890
+
+#include <xml-cxx/xml.hxx>
+#include <iostream>
+#include <sstream>
+
+class A: public xml::Serialize {
+  public:
+    xml::Optional<int> a;
+    xml::Optional<std::string> txt;
+  protected:
+    void initXmlMembers() {
+      className("A");
+      persist(a, "a");
+      persist(txt, "txt");
+    }
+};
+
+class B: public xml::Serialize {
+  public:
+    xml::Optional<A> a;
+    xml::Optional<int> i;
+    xml::Optional<std::string> txt;
+  protected:
+    void initXmlMembers() {
+      className("B");
+      persist(a, "a");
+      persist(i, "i");
+      persist(txt, "txt");
+    }
+};
+
+int main(int, char**) {
+  { // Serialization as a member
+    std::stringstream ss("<B><a><txt>Only this text is given</txt></a></B>");
+    B b;
+    b.loadXml(ss);
+    b.saveXml(std::cout)<<std::endl;
+  }
+  return 0;
+}