pub unsafe extern "C" fn CRYPTO_set_mem_functions(
malloc_fn: Option<unsafe extern "C" fn(usize, *const i8, i32) -> *mut c_void>,
realloc_fn: Option<unsafe extern "C" fn(*mut c_void, usize, *const i8, i32) -> *mut c_void>,
free_fn: Option<unsafe extern "C" fn(*mut c_void, *const i8, i32)>,
) -> i32