Fixed bug in writing string attributes.

xbob/boosting/cpp/lutmachine.cpp

@@ -86,5 +86,5 @@ void LUTMachine::load(bob::io::HDF5File& file){
 void LUTMachine::save(bob::io::HDF5File& file) const{
   file.setArray("LUT", m_look_up_tables);
   file.setArray("Indices", m_indices);
-  file.setAttribute(".", "MachineType", "LUTMachine");
-}
\ No newline at end of file
+  file.setAttribute(".", "MachineType", std::string("LUTMachine"));
+}

xbob/boosting/cpp/stumpmachine.cpp

@@ -60,5 +60,5 @@ void StumpMachine::save(bob::io::HDF5File& file) const{
   file.set("Threshold", m_threshold);
   file.set("Polarity", m_polarity);
   file.set("Index", m_index);
-  file.setAttribute(".", "MachineType", "StumpMachine");
-}
\ No newline at end of file
+  file.setAttribute(".", "MachineType", std::string("StumpMachine"));
+}