[boost] [boost-spirit-qi] Support for n-ary operators PR

Subject: [boost] [boost-spirit-qi] Support for n-ary operators PR
From: Frank Hein (frank.hein_at_[hidden])
Date: 2016-08-06 19:52:08

Hello,

some days ago I raised an PR (https://github.com/boostorg/spirit/pull/200) 
which  adds support for a new class of parsers, in particular named n-ary 
operators.
Joel de Guzman reviewed that. The code is ok. Because this addition 
touches the inner core of qi, the metagrammar, Joel asked me to drum for 
support in the community.

So if you are in qi, may I kindly ask you to review this PR, the code, the 
discussion so far, and respond, if you want to support this PR or if you 
think, it's not needed.
Thank you very much. I highly appreciate your feedback.

The PR description is very detailled, so this mail has not to be. :)

Regards, Frank