[boost] [program_options] Deprecating 'implicit' and 'multitoken' options

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-02-28 10:50:18

Hello,
the program options library allows to mark an option as "implicit". That mean 
that specifying a value on the command line is optional. One can write either

   --someoption foo

or 

   --someoption --someotheroption

In the first case, the --someoption has a value 'foo', and in the second case, 
it has no explicit value. This behaviour is tricky -- we try to look at the 
next token and figure out if it's option or not. In particular, we'll fail 
for the case of

   --someoption -1

and we'll also fail for the case where the token following "--someoption" is 
an option recognized by the user-provided "additional parser".

I would like to deprecate the 'implicit' options and eventually remove them. 
Another alternative is to require that value for implicit options is 
specified in the same token:

   --someoption=foo

Another problem is with the "multitoken" options. Those are options which 
allow the value to span several tokens on the command line. Again, we need to 
check, for each token, if it looks like option or like value, and this is 
tricky. I'd like to deprecate this behaviour as well.

Any objections?

- Volodya