/in/hash.c:78:29: error: implicit declaration of function 'search' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
    node* toDelete = (node*)search(hashtable, size, key);
                            ^
/in/hash.c:78:29: note: did you mean 'bsearch'?
/usr/include/x86_64-linux-gnu/bits/stdlib-bsearch.h:20:1: note: 'bsearch' declared here
bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
^
/in/hash.c:78:22: error: cast to 'node *' (aka 'struct _node *') from smaller integer type 'int' [-Werror,-Wint-to-pointer-cast]
    node* toDelete = (node*)search(hashtable, size, key);
                     ^
/in/hash.c:95:7: error: conflicting types for 'search'
void *search(void *hashtable, int size, int key) {
      ^
/in/hash.c:78:29: note: previous implicit declaration is here
    node* toDelete = (node*)search(hashtable, size, key);
                            ^
3 errors generated.