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