+void Layout::sensor_state_changed(Sensor &sensor, Sensor::State state)
+{
+ if(state==Sensor::ACTIVE)
+ {
+ Block *block = sensor.get_block();
+ if(block && !block->get_train())
+ emergency(block, "Unreserved sensor triggered");
+ }
+}
+
+void Layout::block_reserved(Block &block, Train *train)
+{
+ if(emitting_block_reserved)
+ block_reserve_queue.push_back(BlockReservation(block, train));
+ else
+ {
+ SetFlag setf(emitting_block_reserved);
+ signal_block_reserved.emit(block, train);
+ while(!block_reserve_queue.empty())
+ {
+ BlockReservation br = block_reserve_queue.front();
+ block_reserve_queue.pop_front();
+ signal_block_reserved.emit(br.block, br.train);
+ }
+ }
+}
+
+
+template<typename B>
+Layout::Storage<B>::~Storage()
+{
+ while(!base.empty())
+ delete *base.begin();
+}
+
+template<typename B>
+bool Layout::Storage<B>::insert(B &b)
+{
+ bool result = base.insert(&b).second;
+ if(result)
+ caches.clear();
+ return result;
+}
+
+template<typename B>
+bool Layout::Storage<B>::erase(B &b)
+{
+ bool result = base.erase(&b);
+ if(result)
+ caches.clear();
+ return result;
+}
+
+template<typename B>
+template<typename T>
+const set<T *> &Layout::Storage<B>::get() const
+{
+ for(list<Variant>::const_iterator i=caches.begin(); i!=caches.end(); ++i)
+ if(i->check_type<set<T *> >())
+ return i->value<set<T *> >();
+
+ caches.push_back(set<T *>());
+ set<T *> &result = caches.back().value<set<T *> >();
+ for(typename set<B *>::const_iterator i=base.begin(); i!=base.end(); ++i)
+ if(T *t = dynamic_cast<T *>(*i))
+ result.insert(t);
+
+ return result;
+}
+
+template<typename B>
+template<typename T>
+void Layout::Storage<B>::del()