title: Boost serialization and namespace
body: <p>I'm new using Boost serialization. I'm using xml serialization and the non intrusive version. I followed the tutorial (from Boost website) step by step and my code works fine.</p>
  
  <p>The problem arise when I put my class (the code is divided in .h and .cpp plus a main.cpp file) in a <strong>namespace</strong> (ns_mytests). In this case the compiler (g++) complains and I have the following errors:</p>
  
  <pre><code>g++ -c -g test.o.d -o build/Debug/GNU-Linux-x86/sources/test.o sources/test.cpp
  /opt/local/include/boost/serialization/split_free.hpp: In static member function 'static void boost::serialization::free_saver&lt;Archive, T&gt;::invoke(Archive&amp;, const T&amp;, unsigned int) [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]':
  /opt/local/include/boost/serialization/split_free.hpp:74:   instantiated from 'void boost::serialization::split_free(Archive&amp;, T&amp;, unsigned int) [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]'
  sources/test.h:117:   instantiated from 'void boost::serialization::serialize(Archive&amp;, ns_mytests::Test&amp;, unsigned int) [with Archive = boost::archive::xml_oarchive]'
  /opt/local/include/boost/serialization/serialization.hpp:128:   instantiated from 'void boost::serialization::serialize_adl(Archive&amp;, T&amp;, unsigned int) [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]'
  /opt/local/include/boost/archive/detail/oserializer.hpp:148:   instantiated from 'void boost::archive::detail::oserializer&lt;Archive, T&gt;::save_object_data(boost::archive::detail::basic_oarchive&amp;, const void*) const [with Archive = boost::archive::xml_oarchive, T = ns_mytests::Test]'
  sources/test.cpp:146:   instantiated from here
  /opt/local/include/boost/serialization/split_free.hpp:45: error: no matching function for call to 'save(boost::archive::xml_oarchive&amp;, const ns_mytests::Test&amp;, const boost::serialization::version_type&amp;)'
  make[2]: *** [build/Debug/GNU-Linux-x86/sources/test.o] Error 1
  make[1]: *** [.build-conf] Error 2
  make: *** [.build-impl] Error 2
  </code></pre>
  
  <p>It's sure that I'm doing wrong something, but I could't find my error.</p>
  
  <p>Any help is appreciated.</p>
  
  <p>Thanks,
  westfork</p>