typedef struct treeNode { char* name; char* desc; char* class; //in case we need it double branch_length; SV* obj; // the perlobj SV* obj_ref; // the ref to the perlobj struct treeNode *parent; } Node; SV* new(char* class, char* name, char* desc, double branch_length) { Node* node = malloc(sizeof(Node)); node->obj_ref = newSViv(0); node->obj = newSVrv(obj_ref, class); node->class = savepv(class); node->name = savepv(name); node->desc = savepv(desc); node->branch_length = branch_length; node->parent = NULL; // no parent yet sv_setiv(node->obj, (IV)node); SvREADONLY_on(node->obj); return node->obj_ref; } SV* get_parent(SV* obj) { Node *node = (Node *)SvIV(SvRV(obj)); if(node != NULL && node->parent != NULL) return node->parent->obj_ref; else return NULL; // not sure }