Function guile_sys::__gmp_set_memory_functions

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