Hi, I would like to know if it's possible, with program_options, to handle the order in which several values of the same options are entered. E.g. : when entering prog -f file1.txt -n 2 -f file2.txt -n 3 I need to get the (f,n) couples right, and the use of the -n option should be mandatory for each file. How is it possible to enforce that? or does it all belong to the post-processing of the options ? Regards, Patrick