Benchmark: timing 200000 iterations of A_unpack_line_no_array, substr_into_array, substr_no_array, unpack_line_into_array, unpack_line_no_array...
A_unpack_line_no_array:  2 wallclock secs ( 2.53 usr +  0.00 sys =  2.53 CPU) @ 79051.38/s (n=200000)
substr_into_array:  3 wallclock secs ( 4.02 usr +  0.00 sys =  4.02 CPU) @ 49751.24/s (n=200000)
substr_no_array:  1 wallclock secs ( 0.84 usr +  0.00 sys =  0.84 CPU) @ 238095.24/s (n=200000)
unpack_line_into_array:  4 wallclock secs ( 4.22 usr +  0.00 sys =  4.22 CPU) @ 47393.36/s (n=200000)
unpack_line_no_array:  2 wallclock secs ( 2.10 usr +  0.00 sys =  2.10 CPU) @ 95238.10/s (n=200000)
                           Rate unpack_line_into_array substr_into_array A_unpack_line_no_array unpack_line_no_array substr_no_array
unpack_line_into_array  47393/s                     --               -5%                   -40%                 -50%            -80%
substr_into_array       49751/s                     5%                --                   -37%                 -48%            -79%
A_unpack_line_no_array  79051/s                    67%               59%                     --                 -17%            -67%
unpack_line_no_array    95238/s                   101%               91%                    20%                   --            -60%
substr_no_array        238095/s                   402%              379%                   201%                 150%              --