Function librocksdbsys::crocksdb_merge

pub unsafe extern "C" fn crocksdb_merge(
    db: *mut DBInstance, 
    writeopts: *const DBWriteOptions, 
    k: *const u8, 
    kLen: size_t, 
    v: *const u8, 
    vLen: size_t, 
    err: *mut *mut c_char
)