I suggest to substitute "multiple_sources.cpp" on an offered variant.

[Alex Bukreev <bucreev@…>]

The offered variant shows possibility of the assign in the command line of a filename of a configuration.

[Sascha Ochsenknecht]

(In [58289]) Enhance example, Fixes #3751, Patch from Alex Bukreev

[Sascha Ochsenknecht]

Thanks for enhancement.

I did some small modifications (removed tabs, converted via dos2unix ...). There was also one problem: The value from command line is stored in config_file only after notify() call. I fixed that.

[Alex Bukreev <bucreev@…>]

Excuse, but this example has entered in contradicted with new (very useful) property "required". After the first call "notify (vm)" the exception for the options which values are set in the configuration file will be generated. How to be now I do not know. Probably to enter new function for stock-taking of all demanded options.

[Sascha Ochsenknecht]

Hm, I'm not sure of what you're talking about? What exception do you mean? What do you try?

Thanks, Sascha

[Alex Bukreev <bucreev@…>]

if lines 47-48: "("optimization", po::value<int>(&opt)->default_value(10),"optimization level")" change to: "("optimization", po::value<int>(&opt)->required(),"optimization level")" and exec: multiple_sources.exe there will be an exception in lines 77 (first "notify(vm);").

[Sascha Ochsenknecht]

Yes, the "required" check is done in notify().

You can try not to store in existing variables and then remove the first notify() call:

("optimization", po::value<int>()->default_value(10),"optimization level")

I'm going to check why values for existing variables are applied in notify() ...

[Sascha Ochsenknecht]

example

[Sascha Ochsenknecht]

see attached file required_test.patch for better understanding.

[Alex Bukreev <bucreev@…>]

Thanks for patch. But it does not work. The default value comes back.

[Sascha Ochsenknecht]

Hm, I can not reproduce, debugger shows that config_file is set correctly after the following line:

       string config_file = vm["config"].as< string >();

(default if not given on command line, otherwise set to value given on command line. I use current trunk version

[bucreev@…]

Excuse. I did not set parametre in the command line, therefore and received "defaulted ()".

[bucreev@…]

I suggest to enter your code as an example "multiple_sources.cpp".