pub unsafe extern "C" fn __gmp_set_memory_functions(
arg1: Option<extern "C" fn(arg1: size_t) -> *mut c_void>,
arg2: Option<unsafe extern "C" fn(arg1: *mut c_void, arg2: size_t, arg3: size_t) -> *mut c_void>,
arg3: Option<unsafe extern "C" fn(arg1: *mut c_void, arg2: size_t)>,
)