pub unsafe extern "C" fn rocksdb_mergeoperator_create(
state: *mut c_void,
destructor: Option<unsafe extern "C" fn(_: *mut c_void)>,
full_merge: Option<unsafe extern "C" fn(_: *mut c_void, _: *const c_char, _: size_t, _: *const c_char, _: size_t, _: *const *const c_char, _: *const size_t, _: c_int, _: *mut c_uchar, _: *mut size_t) -> *mut c_char>,
partial_merge: Option<unsafe extern "C" fn(_: *mut c_void, _: *const c_char, _: size_t, _: *const *const c_char, _: *const size_t, _: c_int, _: *mut c_uchar, _: *mut size_t) -> *mut c_char>,
delete_value: Option<unsafe extern "C" fn(_: *mut c_void, _: *const c_char, _: size_t)>,
name: Option<unsafe extern "C" fn(_: *mut c_void) -> *const c_char>
) -> *mut rocksdb_mergeoperator_t