Re: [Boost-users] implicit() in program_options::value_semantic

Alterman, Eugene wrote:

Program options library overview doc illustrates using implicit() for specifying 0 or 1 token value, but this function does not seem to be present in reference doc or source files (as of 1.33.1).

Yes, that method was removed on 2005-04-22. The motivation is that it just leads to parsing ambiguities and no good command line interface I ever seen uses optional values. - Volodya