ENH: OTB-134/OGR first draft of layers iterator

Code/UtilitiesAdapters/OGRAdapters/otbOGRDataSourceWrapper.cxx

@@ -122,6 +122,30 @@ otb::ogr::DataSource::New(OGRDataSource * source)
 /*===========================================================================*/
 /*================================[ layers ]=================================*/
 /*===========================================================================*/
+otb::ogr::DataSource::const_iterator otb::ogr::DataSource::cbegin() const
+{
+  // return const_iterator(*this, 0);
+  assert(!"not-ready");
+  return const_iterator();
+}
+
+otb::ogr::DataSource::const_iterator otb::ogr::DataSource::cend() const
+{
+  // return const_iterator(*this, GetLayersCount());
+  assert(!"not-ready");
+  return const_iterator();
+}
+
+otb::ogr::DataSource::iterator otb::ogr::DataSource::begin()
+{
+  return iterator(*this, 0);
+}
+
+otb::ogr::DataSource::iterator otb::ogr::DataSource::end()
+{
+  return iterator(*this, GetLayersCount());
+}
+
 otb::ogr::Layer otb::ogr::DataSource::CreateLayer(
   std::string const& name,
   OGRSpatialReference * poSpatialRef/* = NULL */,