That works fine when I set the const from the command line when building:
$ nim c -r -d:is_it_for_algo_N=1 algo_1
$ nim c -r -d:is_it_for_algo_N=2 algo_2
Run
But it isn't enough to "set" the const in the algo-specific source file:
# In algo_<X>.nim
const is_it_for_algo_N {.intdefine.} = 1
import algo_common
Run
where your sample code is in algo_common.nim.
I had hoped to keep this sort of config/compile-time setup in the .nim source
files so there is only one place to look, but supplying the correct value at
build time via the algo_<X>.nim.cfg is not a hardship.
(BTW: how can I insert a decorated username in my forum replies when
responding?)