Benchmark: timing 50000 iterations of foo_or, foo_qs...
    foo_or:  2 wallclock secs ( 1.28 usr +  0.00 sys =  1.28 CPU) @ 39062.50/s (n=50000)
    foo_qs:  2 wallclock secs ( 1.21 usr +  0.00 sys =  1.21 CPU) @ 41322.31/s (n=50000)
          Rate foo_or foo_qs
foo_or 39062/s     --    -5%
foo_qs 41322/s     6%     --