Store the number of hydro and gravity particles as a size_t.

src/velociraptor_interface.c

@@ -151,8 +151,8 @@ void velociraptor_invoke(struct engine *e) {
 
     struct space *s = e->s;
     struct gpart *gparts = s->gparts;
-    const int nr_gparts = s->nr_gparts;
-    const int nr_hydro_parts = s->nr_parts;
+    const size_t nr_gparts = s->nr_gparts;
+    const size_t nr_hydro_parts = s->nr_parts;
     const int nr_cells = s->nr_cells;
     int *cell_node_ids;
 

src/velociraptor_interface.h

@@ -69,7 +69,7 @@ struct siminfo {
 
 /* VELOCIraptor interface. */
 int InitVelociraptor(char* config_name, char* output_name, struct cosmoinfo cosmo_info, struct unitinfo unit_info, struct siminfo sim_info);
-int InvokeVelociraptor(const int num_gravity_parts, const int num_hydro_parts, struct gpart *gravity_parts, const int *cell_node_ids, char* output_name);
+int InvokeVelociraptor(const size_t num_gravity_parts, const size_t num_hydro_parts, struct gpart *gravity_parts, const int *cell_node_ids, char* output_name);
 
 /* VELOCIraptor wrapper functions. */
 void velociraptor_init(struct engine *e);