What filename do you want to read? run2.txt
Read: append a 10
Supervector a: [10] size=1 cap=3
Supervector b: [] size=0 cap=3

Read: append a 20
Supervector a: [10 20] size=2 cap=3
Supervector b: [] size=0 cap=3

Read: append a 30
Supervector a: [10 20 30] size=3 cap=3
Supervector b: [] size=0 cap=3

Read: append a 40
Supervector a: [10 20 30 40] size=4 cap=6
Supervector b: [] size=0 cap=3

Read: append b -2
Supervector a: [10 20 30 40] size=4 cap=6
Supervector b: [-2] size=1 cap=3

Read: append b a
Supervector a: [10 20 30 40] size=4 cap=6
Supervector b: [-2 10 20 30 40] size=5 cap=5

Read: append a b
Supervector a: [10 20 30 40 -2 10 20 30 40] size=9 cap=9
Supervector b: [-2 10 20 30 40] size=5 cap=5