From ab7a3804e75f5fecefd46b1e89a6c86454056b2c Mon Sep 17 00:00:00 2001
From: Elias Fleckenstein <eliasfleckenstein@web.de>
Date: Thu, 14 Apr 2022 18:15:10 +0200
Subject: [PATCH] Use void pointers for callback args

---
 array.c                  | 13 +++++++------
 array.h                  |  7 +++----
 bits/wrappers.h          | 14 ++++++++------
 list.c                   | 17 +++++++++--------
 list.h                   | 13 ++++++-------
 map.c                    | 11 ++++++-----
 map.h                    | 11 +++++------
 queue.c                  |  9 +++++----
 queue.h                  |  5 ++---
 refcount.c               |  5 +++--
 refcount.h               |  5 ++---
 test/test_array.c        |  6 +++---
 test/test_list.c         |  4 ++--
 test/test_refcount_map.c | 32 ++++++++++++++------------------
 test/test_tree.c         |  6 +++---
 tree.c                   |  7 ++++---
 tree.h                   | 13 ++++++-------
 17 files changed, 88 insertions(+), 90 deletions(-)

diff --git a/array.c b/array.c
index 27cf55b..714fa4d 100644
--- a/array.c
+++ b/array.c
@@ -1,6 +1,7 @@
-#include <stdlib.h> // for malloc, realloc, free, qsort
-#include <string.h> // for memmove, memcpy
+#include <stdlib.h>        // for malloc, realloc, free, qsort
+#include <string.h>        // for memmove, memcpy
 #include "array.h"
+#include "bits/callback.h" // for Comparator
 
 void array_ini(Array *array, size_t mbs, size_t ext)
 {
@@ -81,12 +82,12 @@ void array_clr(Array *array)
 	array_ini(array, array->mbs, array->ext);
 }
 
-void array_srt(Array *array, Comparator cmp)
+void array_srt(Array *array, void *cmp)
 {
 	qsort(array->ptr, array->siz, array->mbs, cmp);
 }
 
-ssize_t array_fnd(Array *array, const void *ptr, size_t *idx, Comparator cmp)
+ssize_t array_fnd(Array *array, const void *ptr, size_t *idx, void *cmp)
 {
 	size_t low, high, mid;
 
@@ -96,7 +97,7 @@ ssize_t array_fnd(Array *array, const void *ptr, size_t *idx, Comparator cmp)
 	while (low < high) {
 		mid = (low + high) / 2;
 
-		int rel = cmp(ptr, array->ptr + mid * array->mbs);
+		int rel = ((Comparator) cmp)(ptr, array->ptr + mid * array->mbs);
 
 		if (rel == 0)
 			return idx ? (*idx = mid) : mid;
@@ -112,7 +113,7 @@ ssize_t array_fnd(Array *array, const void *ptr, size_t *idx, Comparator cmp)
 	return -1;
 }
 
-size_t array_ins(Array *array, const void *ptr, Comparator cmp)
+size_t array_ins(Array *array, const void *ptr, void *cmp)
 {
 	size_t n;
 
diff --git a/array.h b/array.h
index f71386b..deeea1c 100644
--- a/array.h
+++ b/array.h
@@ -12,7 +12,6 @@
 
 #include <stddef.h>        // for size_t
 #include <sys/types.h>     // for ssize_t
-#include "bits/callback.h" // for Comparator
 #include "bits/compare.h"  // for cmp_ref (not used in file)
 
 typedef struct {
@@ -139,7 +138,7 @@ void array_clr(Array *array);
 	After this, the array is empty and can be reused.
 */
 
-void array_srt(Array *array, Comparator cmp);
+void array_srt(Array *array, void *cmp);
 /*
 	Sorts the array using the quicksort algorithm.
 
@@ -147,7 +146,7 @@ void array_srt(Array *array, Comparator cmp);
 	Wraps the qsort C-library routine. Please refer to it's documentation.
 */
 
-ssize_t array_fnd(Array *array, const void *ptr, size_t *idx, Comparator cmp);
+ssize_t array_fnd(Array *array, const void *ptr, size_t *idx, void *cmp);
 /*
 	Searches the sorted array for the element ptr.
 	Returns the index of the element, or -1 if it wasn't found.
@@ -159,7 +158,7 @@ ssize_t array_fnd(Array *array, const void *ptr, size_t *idx, Comparator cmp);
 		and the order has been kept and the same comparator is used.
 */
 
-size_t array_ins(Array *array, const void *ptr, Comparator cmp);
+size_t array_ins(Array *array, const void *ptr, void *cmp);
 /*
 	Inserts an element into a sorted array, keeping the order.
 	Returns the index the element has been inserted at.
diff --git a/bits/wrappers.h b/bits/wrappers.h
index 5985519..62bce2b 100644
--- a/bits/wrappers.h
+++ b/bits/wrappers.h
@@ -1,26 +1,28 @@
+#include "callback.h" // for Transformer, Callback
+
 #define WRAP_NODE_FUNCTIONS(Type, prefix) \
-	bool prefix ## add(Type *self, void *dat, Comparator cmp, Transformer trans) \
+	bool prefix ## add(Type *self, void *dat, void *cmp, void *trans) \
 	{ \
 		Type ## Node **node = prefix ## nfd(self, dat, cmp); \
  \
 		if (*node) \
 			return false; \
  \
-		prefix ## nmk(self, node, trans ? trans(dat) : dat); \
+		prefix ## nmk(self, node, trans ? ((Transformer) trans)(dat) : dat); \
 		return true; \
 	} \
  \
-	void *prefix ## get(Type *self, void *key, Comparator cmp, Transformer trans) \
+	void *prefix ## get(Type *self, void *key, void *cmp, void *trans) \
 	{ \
 		Type ## Node **node = prefix ## nfd(self, key, cmp); \
  \
 		if (!*node) \
 			return NULL; \
  \
-		return trans ? trans((*node)->dat) : (*node)->dat; \
+		return trans ? ((Transformer) trans)((*node)->dat) : (*node)->dat; \
 	} \
  \
-	bool prefix ## del(Type *self, void *key, Comparator cmp, Callback call, void *arg, Transformer trans) \
+	bool prefix ## del(Type *self, void *key, void *cmp, void *call, void *arg, void *trans) \
 	{ \
 		Type ## Node **node = prefix ## nfd(self, key, cmp); \
  \
@@ -28,7 +30,7 @@
 			return false; \
  \
 		if (call) \
-			call(trans ? trans((*node)->dat) : (*node)->dat, arg); \
+			((Callback) call)(trans ? ((Transformer) trans)((*node)->dat) : (*node)->dat, arg); \
  \
 		prefix ## nrm(self, node); \
 		return true; \
diff --git a/list.c b/list.c
index a4aba67..8036a2a 100644
--- a/list.c
+++ b/list.c
@@ -1,5 +1,6 @@
-#include <stdlib.h> // for malloc, free
-#include <string.h> // for strcmp
+#include <stdlib.h>        // for malloc, free
+#include <string.h>        // for strcmp
+#include "bits/callback.h" // for Callback, Comparator, Transformer
 #include "bits/wrappers.h"
 #include "list.h"
 
@@ -25,12 +26,12 @@ void list_ppd(List *list, void *dat)
 	list->fst->nxt = fst;
 }
 
-ListNode **list_nfd(List *list, void *key, Comparator cmp)
+ListNode **list_nfd(List *list, void *key, void *cmp)
 {
 	ListNode **node;
 
 	for (ITER_REFS)
-		if (cmp((*node)->dat, key) == 0)
+		if (((Comparator) cmp)((*node)->dat, key) == 0)
 			return node;
 
 	return node;
@@ -57,19 +58,19 @@ void list_nrm(List *list, ListNode **node)
 	free(old);
 }
 
-void list_itr(List *list, Callback iter, void *arg, Transformer trans)
+void list_itr(List *list, void *iter, void *arg, void *trans)
 {
 	LIST_ITERATE(list, node)
-		iter(trans ? trans(node->dat) : node->dat, arg);
+		((Callback) iter)(trans ? ((Transformer) trans)(node->dat) : node->dat, arg);
 }
 
-void list_clr(List *list, Callback iter, void *arg, Transformer trans)
+void list_clr(List *list, void *iter, void *arg, void *trans)
 {
 	for (ListNode *node = list->fst; node != NULL;) {
 		ListNode *next = node->nxt;
 
 		if (iter)
-			iter(trans ? trans(node->dat) : node->dat, arg);
+			((Callback) iter)(trans ? ((Transformer) trans)(node->dat) : node->dat, arg);
 
 		free(node);
 		node = next;
diff --git a/list.h b/list.h
index 16fd46b..4a7333b 100644
--- a/list.h
+++ b/list.h
@@ -9,7 +9,6 @@
 #define _DRAGONSTD_LIST_H_
 
 #include <stdbool.h>       // for bool
-#include "bits/callback.h" // for Callback, Comparator, Transformer, Callback
 #include "bits/compare.h"  // for cmp_ref (not used in file)
 
 #define LIST_ITERATE(list, node) for (ListNode *node = (list)->fst; node != NULL; node = node->nxt)
@@ -35,7 +34,7 @@ void list_ini(List *list);
 	This function should be called before any other function is called on the list.
 */
 
-bool list_add(List *list, void *dat, Comparator cmp, Transformer trans);
+bool list_add(List *list, void *dat, void *cmp, void *trans);
 /*
 	Add an element to the list.
 
@@ -43,14 +42,14 @@ bool list_add(List *list, void *dat, Comparator cmp, Transformer trans);
 	Return whether an element has been added.
 */
 
-void *list_get(List *list, void *key, Comparator cmp, Transformer trans);
+void *list_get(List *list, void *key, void *cmp, void *trans);
 /*
 	Get an element from the list.
 
 	The first matching element is returned, or NULL if none found.
 */
 
-bool list_del(List *list, void *key, Comparator cmp, Callback call, void *arg, Transformer trans);
+bool list_del(List *list, void *key, void *cmp, void *call, void *arg, void *trans);
 /*
 	Delete an element from the list if it is found.
 	Return whether an element has been deleted.
@@ -68,7 +67,7 @@ void list_ppd(List *list, void *dat);
 	Prepend an element at the start of the list.
 */
 
-ListNode **list_nfd(List *list, void *key, Comparator cmp);
+ListNode **list_nfd(List *list, void *key, void *cmp);
 /*
 	Find the location of the first node matching key.
 
@@ -86,7 +85,7 @@ void list_nrm(List *list, ListNode **node);
 	Remove the node at the given location.
 */
 
-void list_itr(List *list, Callback iter, void *arg, Transformer trans);
+void list_itr(List *list, void *iter, void *arg, void *trans);
 /*
 	Iterate over the list.
 	Calls iter on every element, with the extra argument arg.
@@ -94,7 +93,7 @@ void list_itr(List *list, Callback iter, void *arg, Transformer trans);
 	Note: the LIST_ITERATE macro can be used to do this without function calls.
 */
 
-void list_clr(List *list, Callback iter, void *arg, Transformer trans);
+void list_clr(List *list, void *iter, void *arg, void *trans);
 /*
 	Iterates over the list and deletes all elements.
 	Calls iter on every element, with the extra argument arg.
diff --git a/map.c b/map.c
index 899d25c..81751b4 100644
--- a/map.c
+++ b/map.c
@@ -1,3 +1,4 @@
+#include "bits/callback.h" // for Transformer
 #include "map.h"
 
 static bool get_lock(Map *map, bool write)
@@ -32,7 +33,7 @@ void map_dst(Map *map)
 	pthread_rwlock_destroy(&map->clk);
 }
 
-void map_cnl(Map *map, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order)
+void map_cnl(Map *map, void *iter, void *arg, void *trans, TreeTraversionOrder order)
 {
 	pthread_rwlock_wrlock(&map->clk);
 	map->cnl = true;
@@ -45,7 +46,7 @@ void map_cnl(Map *map, Callback iter, void *arg, Transformer trans, TreeTraversi
 	pthread_rwlock_unlock(&map->tlk);
 }
 
-bool map_add(Map *map, void *dat, Comparator cmp, Transformer trans)
+bool map_add(Map *map, void *dat, void *cmp, void *trans)
 {
 	if (!get_lock(map, true))
 		return false;
@@ -55,7 +56,7 @@ bool map_add(Map *map, void *dat, Comparator cmp, Transformer trans)
 	return ret;
 }
 
-void *map_get(Map *map, void *key, Comparator cmp, Transformer trans)
+void *map_get(Map *map, void *key, void *cmp, void *trans)
 {
 	if (!get_lock(map, false))
 		return NULL;
@@ -65,7 +66,7 @@ void *map_get(Map *map, void *key, Comparator cmp, Transformer trans)
 	return ret;
 }
 
-bool map_del(Map *map, void *key, Comparator cmp, Callback call, void *arg, Transformer trans)
+bool map_del(Map *map, void *key, void *cmp, void *call, void *arg, void *trans)
 {
 	if (!get_lock(map, true))
 		return false;
@@ -75,7 +76,7 @@ bool map_del(Map *map, void *key, Comparator cmp, Callback call, void *arg, Tran
 	return ret;
 }
 
-void map_trv(Map *map, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order)
+void map_trv(Map *map, void *iter, void *arg, void *trans, TreeTraversionOrder order)
 {
 	if (!get_lock(map, false))
 		return;
diff --git a/map.h b/map.h
index 3733b9b..eea5f0e 100644
--- a/map.h
+++ b/map.h
@@ -11,7 +11,6 @@
 
 #include <stdbool.h>       // for bool
 #include <pthread.h>       // for pthread_rwlock_t
-#include "bits/callback.h" // for Transformer, Comparator, Callback
 #include "tree.h"          // for Tree
 
 typedef struct {
@@ -38,7 +37,7 @@ void map_dst(Map *map);
 	Make sure to cancel the map before destroying it, to avoid memory leaks.
 */
 
-void map_cnl(Map *map, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order);
+void map_cnl(Map *map, void *iter, void *arg, void *trans, TreeTraversionOrder order);
 /*
 	[Thread Safe]
 	Cancels and clears the map.
@@ -52,7 +51,7 @@ void map_cnl(Map *map, Callback iter, void *arg, Transformer trans, TreeTraversi
 	If no callback is given, the traversion order is irrelevant.
 */
 
-bool map_add(Map *map, void *dat, Comparator cmp, Transformer trans);
+bool map_add(Map *map, void *dat, void *cmp, void *trans);
 /*
 	[Thread Safe]
 	Add an element to the map.
@@ -61,20 +60,20 @@ bool map_add(Map *map, void *dat, Comparator cmp, Transformer trans);
 	Return whether an element has been added.
 */
 
-void *map_get(Map *map, void *key, Comparator cmp, Transformer trans);
+void *map_get(Map *map, void *key, void *cmp, void *trans);
 /*
 	[Thread Safe]
 	Get an element from the map, or return NULL if none found.
 */
 
-bool map_del(Map *map, void *key, Comparator cmp, Callback call, void *arg, Transformer trans);
+bool map_del(Map *map, void *key, void *cmp, void *call, void *arg, void *trans);
 /*
 	[Thread Safe]
 	Delete an element from the map if it is found.
 	Return whether an element has been deleted.
 */
 
-void map_trv(Map *map, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order);
+void map_trv(Map *map, void *iter, void *arg, void *trans, TreeTraversionOrder order);
 /*
 	[Thread Safe]
 	Traverse the map.
diff --git a/queue.c b/queue.c
index 91c2d31..98613d7 100644
--- a/queue.c
+++ b/queue.c
@@ -1,4 +1,5 @@
-#include <sched.h>
+#include <sched.h>         // for sched_yield
+#include "bits/callback.h" // for Transformer
 #include "queue.h"
 
 void queue_ini(Queue *queue)
@@ -15,7 +16,7 @@ void queue_dst(Queue *queue)
 	pthread_mutex_destroy(&queue->mtx);
 }
 
-void queue_clr(Queue *queue, Callback iter, void *arg, Transformer trans)
+void queue_clr(Queue *queue, void *iter, void *arg, void *trans)
 {
 	list_clr(&queue->lst, iter, arg, trans);
 }
@@ -35,7 +36,7 @@ bool queue_enq(Queue *queue, void *dat)
 	return success;
 }
 
-void *queue_deq(Queue *queue, Transformer trans)
+void *queue_deq(Queue *queue, void *trans)
 {
 	void *dat = NULL;
 
@@ -47,7 +48,7 @@ void *queue_deq(Queue *queue, Transformer trans)
 			list_nrm(&queue->lst, node);
 
 			if (trans)
-				dat = trans(dat);
+				dat = ((Transformer) trans)(dat);
 		} else {
 			pthread_cond_wait(&queue->cnd, &queue->mtx);
 		}
diff --git a/queue.h b/queue.h
index 96fdcfc..cb4ad42 100644
--- a/queue.h
+++ b/queue.h
@@ -11,7 +11,6 @@
 
 #include <pthread.h>       // for pthread_cond_t, pthread_mutex_t
 #include <stdbool.h>       // for bool
-#include "bits/callback.h" // for Transformer
 #include "list.h"          // for List
 
 typedef struct {
@@ -40,7 +39,7 @@ void queue_dst(Queue *queue);
 		list is cleared before calling this function.
 */
 
-void queue_clr(Queue *queue, Callback iter, void *arg, Transformer trans);
+void queue_clr(Queue *queue, void *iter, void *arg, void  *trans);
 /*
 	Clears the queue.
 
@@ -58,7 +57,7 @@ bool queue_enq(Queue *queue, void *dat);
 	Notifies waiting consumer threads.
 */
 
-void *queue_deq(Queue *queue, Transformer trans);
+void *queue_deq(Queue *queue, void *trans);
 /*
 	[Thread Safe]
 	Dequeue an element.
diff --git a/refcount.c b/refcount.c
index 3b36ac7..95d896b 100644
--- a/refcount.c
+++ b/refcount.c
@@ -1,6 +1,7 @@
+#include "bits/callback.h" // for SingleCallback
 #include "refcount.h"
 
-void refcount_ini(Refcount *refcount, void *obj, SingleCallback del)
+void refcount_ini(Refcount *refcount, void *obj, void *del)
 {
 	refcount->obj = obj;
 	refcount->del = del;
@@ -33,7 +34,7 @@ void refcount_drp(Refcount *refcount)
 	pthread_mutex_unlock(&refcount->mtx);
 
 	if (!count)
-		refcount->del(refcount->obj);
+		((SingleCallback) refcount->del)(refcount->obj);
 }
 
 void *refcount_obj(Refcount *refcount)
diff --git a/refcount.h b/refcount.h
index 0efab56..d3d7bd7 100644
--- a/refcount.h
+++ b/refcount.h
@@ -14,17 +14,16 @@
 #define _DRAGONSTD_REFCOUNT_H_
 
 #include <pthread.h>       // for pthread_mutex_t
-#include "bits/callback.h" // for Callback
 
 typedef struct {
 	/* private */
 	void *obj;
-	SingleCallback del;
+	void *del;
 	unsigned short cnt;  // counter
 	pthread_mutex_t mtx; // lock to protect count
 } Refcount;
 
-void refcount_ini(Refcount *refcount, void *obj, SingleCallback del);
+void refcount_ini(Refcount *refcount, void *obj, void *del);
 /*
 	Initializes the refcount.
 
diff --git a/test/test_array.c b/test/test_array.c
index 94e78c7..a6c8e19 100644
--- a/test/test_array.c
+++ b/test/test_array.c
@@ -114,14 +114,14 @@ int main()
 	assert(arr.cap == 8);
 
 	printf("testing srt\n");
-	array_srt(&arr, (void *) &cmp_int);
+	array_srt(&arr, &cmp_int);
 
 	printf("testing order: exp: (sorted) got: "); dump(&arr); printf("\n");
 	assert_in_order(&arr);
 
 	for (size_t j = 0; j < arr.siz; j++) {
 		i = ((int *) arr.ptr)[j];
-		ssize_t s = array_fnd(&arr, &i, NULL, (void *) &cmp_int);
+		ssize_t s = array_fnd(&arr, &i, NULL, &cmp_int);
 
 		printf("testing fnd at index %lu: exp: >=0 got: %ld\n", j, s);
 		assert(s >= 0);
@@ -134,7 +134,7 @@ int main()
 
 	printf("testing ins\n");
 	for (int j = 0; j < 10; j++) {
-		i = rand() % 100; array_ins(&arr, &i, (void *) &cmp_int);
+		i = rand() % 100; array_ins(&arr, &i, &cmp_int);
 	}
 
 	printf("testing order: exp: (sorted) got: "); dump(&arr); printf("\n");
diff --git a/test/test_list.c b/test/test_list.c
index 5dba6d2..3645c04 100644
--- a/test/test_list.c
+++ b/test/test_list.c
@@ -2,9 +2,9 @@
 #include <stdio.h>
 #include "../list.h"
 
-int cmp_int(const void *ia, const void *ib)
+int cmp_int(const int *ia, const int *ib)
 {
-	return *(const int *) ia - *(const int *) ib;
+	return *ia - *ib;
 }
 
 int main()
diff --git a/test/test_refcount_map.c b/test/test_refcount_map.c
index 9d717c1..fc3b5e4 100644
--- a/test/test_refcount_map.c
+++ b/test/test_refcount_map.c
@@ -16,29 +16,25 @@ typedef struct {
 	Refcount rc;
 } DataObject;
 
-void data_object_delete(DataObject *obj)
+int rand_id()
 {
-	refcount_dst(&obj->rc);
-	free(obj);
+	return rand() % 1000;
 }
 
-int rand_id()
+void delete_obj(DataObject *obj)
 {
-	return rand() % 1000;
+	refcount_dst(&obj->rc);
+	free(obj);
 }
 
-int data_object_compare(const void *pa, const void *pb)
+int cmp_obj(const Refcount *rc, const int *id)
 {
-	return
-		((DataObject *) ((const Refcount *) pa)->obj)->id -
-		((DataObject *) ((const Refcount *) pb)->obj)->id;
+	return ((DataObject *) rc->obj)->id - *id;
 }
 
-int data_object_compare_id(const void *pa, const void *pb)
+int cmp_obj_sym(const Refcount *rc1, const Refcount *rc2)
 {
-	return
-		((DataObject *) ((const Refcount *) pa)->obj)->id -
-		*(const int *) pb;
+	return cmp_obj(rc1, &((DataObject *) rc2->obj)->id);
 }
 
 static void *thread_create(unsigned int *result)
@@ -47,9 +43,9 @@ static void *thread_create(unsigned int *result)
 		DataObject *obj = malloc(sizeof *obj);
 		obj->id = rand_id();
 
-		refcount_ini(&obj->rc, obj, (void *) &data_object_delete);
+		refcount_ini(&obj->rc, obj, &delete_obj);
 
-		if (map_add(&map, &obj->rc, &data_object_compare, (void *) &refcount_inc))
+		if (map_add(&map, &obj->rc, &cmp_obj_sym, &refcount_inc))
 			(*result)++;
 
 		refcount_drp(&obj->rc);
@@ -74,7 +70,7 @@ static void *thread_access(unsigned int *result)
 
 		while (!objs[i] && !cancel) {
 			int id = rand_id();
-			objs[i] = map_get(&map, &id, &data_object_compare_id, (void *) &refcount_grb);
+			objs[i] = map_get(&map, &id, &cmp_obj, &refcount_grb);
 		}
 
 		if (objs[i])
@@ -95,7 +91,7 @@ static void *thread_delete(unsigned int *result)
 	while (!cancel) {
 		unsigned int id = rand_id();
 
-		if (map_del(&map, &id, &data_object_compare_id, (void *) &refcount_drp, NULL, NULL))
+		if (map_del(&map, &id, &cmp_obj, &refcount_drp, NULL, NULL))
 			(*result)++;
 	}
 
@@ -136,7 +132,7 @@ int main()
 				results[i][0] += results[i][j];
 		}
 
-	map_cnl(&map, (void *) &refcount_drp, NULL, NULL, 0);
+	map_cnl(&map, &refcount_drp, NULL, NULL, 0);
 	map_dst(&map);
 
 	printf("Time: 1 second\n");
diff --git a/test/test_tree.c b/test/test_tree.c
index dbe9899..005814b 100644
--- a/test/test_tree.c
+++ b/test/test_tree.c
@@ -6,9 +6,9 @@
 
 #define NUM_ELEMENTS 1e5
 
-int cmp_int(const void *ia, const void *ib)
+int cmp_int(const int *ia, const int *ib)
 {
-	return *(const int *) ia - *(const int *) ib;
+	return *ia - *ib;
 }
 
 void clear_callback(int *ia, int *ib)
@@ -68,5 +68,5 @@ int main()
 	}
 
 	int last = -1;
-	tree_clr(&tree, (void *) &clear_callback, &last, NULL, TRAVERSION_INORDER);
+	tree_clr(&tree, &clear_callback, &last, NULL, TRAVERSION_INORDER);
 }
diff --git a/tree.c b/tree.c
index 42ac277..a857789 100644
--- a/tree.c
+++ b/tree.c
@@ -1,4 +1,5 @@
 #include <stdlib.h>  // for malloc, free
+#include "bits/callback.h" // for Callback, Comparator, Transformer
 #include "bits/wrappers.h"
 #include "tree.h"
 
@@ -39,7 +40,7 @@ void tree_ini(Tree *tree)
 
 WRAP_NODE_FUNCTIONS(Tree, tree_)
 
-TreeNode **tree_nfd(Tree *tree, void *key, Comparator cmp)
+TreeNode **tree_nfd(Tree *tree, void *key, void *cmp)
 {
 	return search(&tree->rot, key, cmp);
 }
@@ -68,12 +69,12 @@ void tree_nrm(__attribute__((unused)) Tree *tree, TreeNode **node)
 	free(old);
 }
 
-void tree_trv(Tree *tree, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order)
+void tree_trv(Tree *tree, void *iter, void *arg, void *trans, TreeTraversionOrder order)
 {
 	traverse(tree->rot, iter, arg, trans, order, 0);
 }
 
-void tree_clr(Tree *tree, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order)
+void tree_clr(Tree *tree, void *iter, void *arg, void *trans, TreeTraversionOrder order)
 {
 	traverse(tree->rot, iter, arg, trans, order, 1);
 	tree_ini(tree);
diff --git a/tree.h b/tree.h
index 2ce1b11..5c27105 100644
--- a/tree.h
+++ b/tree.h
@@ -15,7 +15,6 @@
 #define _DRAGONSTD_TREE_H_
 
 #include <stdbool.h>       // for bool
-#include "bits/callback.h" // for Callback, Comparator, Transformer, Callback
 #include "bits/compare.h"  // for cmp_ref (not used in file)
 
 typedef struct TreeNode {
@@ -45,7 +44,7 @@ void tree_ini(Tree *tree);
 	This function should be called before any other function is called on the tree.
 */
 
-bool tree_add(Tree *tree, void *dat, Comparator cmp, Transformer trans);
+bool tree_add(Tree *tree, void *dat, void *cmp, void *trans);
 /*
 	Add an element to the tree.
 
@@ -53,18 +52,18 @@ bool tree_add(Tree *tree, void *dat, Comparator cmp, Transformer trans);
 	Return whether an element has been added.
 */
 
-void *tree_get(Tree *tree, void *key, Comparator cmp, Transformer trans);
+void *tree_get(Tree *tree, void *key, void *cmp, void *trans);
 /*
 	Get an element from the tree, or return NULL if none found.
 */
 
-bool tree_del(Tree *tree, void *key, Comparator cmp, Callback call, void *arg, Transformer trans);
+bool tree_del(Tree *tree, void *key, void *cmp, void *call, void *arg, void *trans);
 /*
 	Delete an element from the tree if it is found.
 	Return whether an element has been deleted.
 */
 
-TreeNode **tree_nfd(Tree *tree, void *key, Comparator cmp);
+TreeNode **tree_nfd(Tree *tree, void *key, void *cmp);
 /*
 	Find the location of a node matching key.
 
@@ -82,13 +81,13 @@ void tree_nrm(Tree *tree, TreeNode **node);
 	Remove the node at the given location.
 */
 
-void tree_trv(Tree *tree, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order);
+void tree_trv(Tree *tree, void *iter, void *arg, void *trans, TreeTraversionOrder order);
 /*
 	Traverse the tree.
 	Calls iter on every element, with the extra argument arg.
 */
 
-void tree_clr(Tree *tree, Callback iter, void *arg, Transformer trans, TreeTraversionOrder order);
+void tree_clr(Tree *tree, void *iter, void *arg, void *trans, TreeTraversionOrder order);
 /*
 	Traverses the tree and deletes all elements.
 	Calls iter on every element, with the extra argument arg.
-- 
2.44.0