Function libffi::raw::ffi_prep_closure

pub unsafe extern "C" fn ffi_prep_closure(
    arg1: *mut ffi_closure,
    arg2: *mut ffi_cif,
    fun: Option<unsafe extern "C" fn(_: *mut ffi_cif, _: *mut c_void, _: *mut *mut c_void, _: *mut c_void)>,
    user_data: *mut c_void
) -> u32