+simgrid::xbt::signal<void(s4u::Storage&)> Storage::on_creation;
+simgrid::xbt::signal<void(s4u::Storage&)> Storage::on_destruction;
+simgrid::xbt::signal<void(s4u::Storage&)> Storage::on_state_change;
+
+Storage::Storage(const std::string& name, surf::StorageImpl* pimpl) : pimpl_(pimpl), name_(name)