Re: [Boost-users] [Program Options] terminate parsing after first positional argument

Subject: Re: [Boost-users] [Program Options] terminate parsing after first positional argument
From: Evan Driscoll (driscoll_at_[hidden])
Date: 2012-07-05 19:54:19

On 07/05/2012 06:07 PM, Evan Driscoll wrote:
> On 01/-10/-28163 01:59 PM, Vladimir Prus wrote:
>> that patch of yours looks perfectly reasonable to me. It would seem that
>> a style option, e.g. 'allow_intermixed' can be used to control
>> this behaviour (with the current behaviour as default).
>
> Can I just run the plan by you then?

OK, this is not as clear as I was thinking. (Surprise surprise!)

As phrased, this is a backwards-incompatible change. If a client of the 
library builds their own style_t value from scratch (as opposed to 
starting from default_style and setting/unsetting bits in that), they'll 
not set allow_interspersed, and lose interspersed arguments.

This was illustrated by the fact that I had to modify three style_t 
declarations in cmdline_test.cpp to fix test cases that I broke. (Lines 
368, 397, and 412 or thereabouts.) If I just pass a literal false as in 
my original patch, everything is peachy in the unmodified test cases. 
(I'm not sure I understand why the test cases were failing, but that's 
probably just because I don't have a holistic enough view of how the 
test cases are written.)

How should I handle this? Cleanest way I can think of that doesn't break 
compatibility is to add a 'allow_interspersed' style option instead with 
the opposite sense, but everything else is 'allow_*'.

Evan