Return value pattern produces an error when entering multidimensional arrays

The following code produces an error, even though it shouldn't.

int[*]{n} foo( int[m:shp] n)
{
    return [[42,21,2]];
}

int main () {
    StdIO::print ( foo (_hideValue_SxA_(1, [[42,21,2]])) );
    return 0;
}