Re: [Boost-users] [program options] vectro from config file

Diederick C. Niehorster wrote:

Hi Volodya,

Thank you for your reply. I have placed my code, improved, into the validate() function now (see below). Thats a good idea anyway, this way it works on input from any source. I am still stuck with the issue of how to test whether users specified a vector or not as return target in their options_description, that is: ("Tex.GaussSigma", po::value<float>(&fTexGaussSigma) , "Tex.GaussSigma") or ("Tex.Color" , po::value(&vfTexColor), "Expt.Color")

Due to the very complicated flow (if you've just looked at the code for a few hours) I find it hard to figure out. I suppose i have to run typeid(*something*).name() to get the type of some variable and then check if its a vector or not. But what should be in the place of *something*?

I think you are changing the validate overload that is for vectors, not? It won't ever be called for non-vectors.

As a general point, do you think this would be a good addition to the parser, that is, would you want to incorporate this kind of extention into the Boost release? It is a much easier way of specifying a vector, whether on the command line or from another source without having to resort to positional options, which are not a good solution for every source and situation. Compare (for command line) [--test "(1 2)"] with [--test 1 --test 2].

I am not yet sure this is good addition. In any case, it would be better to first allow to specify custom validate function for a given option.

Lastly, in an old post (cant find it now, was 2005 or 2006) a user asked whether it was possible to do po::parse_config_file(InitFileName,poInit,true); instead of po::parse_config_file(ifs,poInit,true); as the documentation apparently reflected this at that point. You replied that you'd fix that at that time (I believe it was you, doesn't really matter), but when i just tried it didnt work. Have you decided against it?

I honestly don't remember. If you care about this change, please file a bug at svn.boost.org, so that it's not forgotted for another 4 years. - Volodya