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How does boost::program_options parse or manage an input when both multitoken and positional options are allowed?

For example:

./app.sample pos1 --multitokenoption a b c d pos2

How does boost know when a multitokenoption finishes and a positional option begins?

Obviously, the most logical allowed behaviour would be that a multitoken option must be present as last parameter, just as happens with default arguments in function parameters, but the documentation says nothing about it.

ABu
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    Why do you think the `multitokenoption` will finish? It will eat all the remaining tokens. If 'pos2' is required, then it will be an exception thrown. – HEKTO May 22 '14 at 21:21

1 Answers1

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There are three way to mark the end of values for a multitoken option:

  1. Another option:

        ./app.sample pos1 --multitokenoption a b c d --regularoption v pos2

  2. Option name for the positional option (almost the #1):

        ./app.sample pos1 --multitokenoption a b c d --pos2 pos2

  3. Double-dash:

        ./app.sample pos1 --multitokenoption a b c d -- pos2

Otherwise the multi-token option won't know where to stop - nothing magical.

HEKTO
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    But boost::program_option has no native support for such double dash, if I'm not wrong. – ABu May 22 '14 at 22:24
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    It works for me. Boost = 1.55.0, Compiler = GCC 4.8.1, OS = Xubuntu 3.11.10.3 – HEKTO May 22 '14 at 22:41