[Boost-users] [program_options] How to allow multiple options?

From: Ian McCulloch (ianmcc_at_[hidden])
Date: 2006-08-16 20:03:46

Hi,

I have spent several hours looking at the docs and sources, but I cannot
figure out how to allow multiple occurances of an option.  Many unix tools
allow you to specify the --verbose option multiple times, to mean
increasing verbosity of output, and I want to replicate this behaviour.

Does this require writing a new class derived from value_semantic, that
combines the behaviour of bool_switch() and
typed_value<std::vector<bool>> ?  I'm not sure how to go about doing that.

It is a very useful lib, but I do wish (often!) there was some real
reference docs (aside from the doxygen stuff and comments in the sources
themselves, which isn't enough :-(

Unrelated, but in trying to figure this out from the docs, I noticed in the
overview.html, in the Syntactic Information there is a call to a function
value<string>()->implicit().  However typed_value<T> has no such member
function.  Maybe it is left over from a previous design iteration or
something, as there is a member variable m_implicit but it is never
initialized or accessed.

Cheers,
Ian McCulloch