void archive_options_extract::set_selection(const mask & selection)
    {
	NLS_SWAP_IN;
	try
	{
	    archive_option_destroy_mask(x_selection);
	    x_selection = selection.clone();
	    if(x_selection == NULL)
		throw Ememory("archive_options_extract::set_selection");
	}
	catch(...)
	{
	    NLS_SWAP_OUT;
	    throw;
	}
	NLS_SWAP_OUT;
    }

KFR_SINTRIN vec<T, N> select(const mask<T, N>& m, const vec<T, N>& x, const vec<T, N>& y)
{
    return y ^ ((x ^ y) & m.asvec());
}

KFR_INTRINSIC vec<Tout, N> select(const mask<T1, N>& m, const T2& x, const T3& y)
{
    static_assert(sizeof(T1) == sizeof(Tout), "select: incompatible types");
    return intrinsics::select(bitcast<Tout>(m.asvec()).asmask(), innercast<Tout>(x), innercast<Tout>(y));
}