* Callbacks *
*************/
-simgrid::surf::signal<void(simgrid::surf::VirtualMachine*)> VMCreatedCallbacks;
-simgrid::surf::signal<void(simgrid::surf::VirtualMachine*)> VMDestructedCallbacks;
-simgrid::surf::signal<void(simgrid::surf::VirtualMachine*)> VMStateChangedCallbacks;
+simgrid::xbt::signal<void(simgrid::surf::VirtualMachine*)> VMCreatedCallbacks;
+simgrid::xbt::signal<void(simgrid::surf::VirtualMachine*)> VMDestructedCallbacks;
+simgrid::xbt::signal<void(simgrid::surf::VirtualMachine*)> VMStateChangedCallbacks;
/*********
* Model *