Vladimir Prus wrote:
Neal D. Becker wrote:
Require that all default_value()'s provide a default value string either from operator << or explicitly when supplying the default value?
default_value(x) -> must support operator <<(x) default_value(x, "x") -> no need for operator <<(x)
Good idea!
True. I've just comitted/uploaded revision 288 which produces the following (don't forget to use fixed font when viewving ;-) )
Usage: options_description [options] Allowed options: --help : produce help message --optimization arg (=10) : optimization level -I [ --include-path ] arg : include path --input-file arg : input file
The (=10) is meant to give default value. The only problem I've found is that we need to specify empty default value string for std::vector, which leads to code like this:
("second", value< vector<int > >()->default_value(vector<int>(1, 1), ""))
Ok, maybe we just need 'vector_value' function which will take care of default values.
You also have the choice of not using default_value. main() { value (1,1); //set default outside of program_options program_options.... So I don't think the case you show above is a serious problem. (Nobody forces you to use default_value if it's not convenient).