#if defined(_MSC_VER)
/* find or insert datum into search tree */
void *tsearch(const void *vkey, void **vrootp,
              int (*compar)(const void *, const void *));

/* delete node with given key */
void * tdelete(const void *vkey, void **vrootp,
               int (*compar)(const void *, const void *));

/* Walk the nodes of a tree */
void twalk(const void *vroot, void (*action)(const void *, VISIT, int));

#else
#include <search.h>
#endif