pub unsafe extern "C" fn rocksdb_mergeoperator_create(
state: *mut c_void,
destroy: extern "C" fn(*mut c_void),
full_merge: extern "C" fn(*mut c_void, *const i8, usize, *const i8, usize, *const *const i8, *const usize, i32, *mut u8, *mut usize) -> *const i8,
partial_merge: extern "C" fn(*mut c_void, *const i8, usize, *const *const i8, *const usize, i32, *mut u8, *mut usize) -> *const i8,
delete_value: Option<extern "C" fn(*mut c_void, *const i8, *mut usize)>,
name_fn: extern "C" fn(*mut c_void) -> *const i8
) -> *const DBMergeOperatorOpaque