In the documentation on program_options (program_options/overview.html), in the section Parsers Component it says "Sometimes it's desirable to specify value as several tokens. For example, an option "--email-recipient" may be followed by several emails, each as a separate command line token. This behaviour is supported, though it can lead to parsing ambiguities and is not enabled by default." This is just what I would like to. However, I haven't found anything in the documentation explaining how to do this. I don't think this can be done using positional options - is this correct? For example, I would like to be able to have command-line options along the lines of: -A 1 2 3 -B hello goodbye and have 1, 2, and 3 stored in a vector of integers associated with the -A flag, and "hello" and "goodbye" in a vector of strings associated with the -B flag. So how do I enable this? Paul Giaccone