  else static if (F[0..2] == "%%")
        enum FormatString = "%" ~ FormatString!(F[2..$],A);
    else
    {
        static assert(F[0] != '%', "unrecognized format %" ~ F[1]);
        enum FormatString = F[0] ~ FormatString!(F[1..$],A);
    }
}

unittest
{
    auto s = Format!("hel%slo", "world", -138, 'c', true);
    assert(s == "helworldlo-138ctrue", "[" ~ s ~ "]");
}

/**
 * Convert constant argument to a string.
 */

template toStringNow(ulong v)
{
    static if (v < 10)
        enum toStringNow = "" 