[Boost-bugs] [Boost C++ Libraries] #8465: ptree get_child should not throw an exception on empty sets

Subject: [Boost-bugs] [Boost C++ Libraries] #8465: ptree get_child should not throw an exception on empty sets
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-04-19 18:45:37

#8465: ptree get_child should not throw an exception on empty sets
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 Reporter:  Dale Stansberry <stansberrydv@…>         |        Type:  Bugs            
   Status:  new                                      |   Milestone:  To Be Determined
Component:  None                                     |     Version:  Boost 1.53.0    
 Severity:  Problem                                  |    Keywords:                  
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 I feel there is an design issue with the ptree::get_child() method related
 to the choice of throwing an exception when reading an empty source. The
 typical use of get_child() employs of a for loop (or BOOST_FOREACH) which
 one expects to exhibit the standard behaviour of a container iterator:
 loop over contained items until finished, and if there are no items, then
 do nothing. Throwing an exception if no child exists does not conform to
 this expected behaviour (and was poorly documented as well...) and it also
 does not really comply with the concept of an exceptional condition (for
 cases where empty/optional sources are expected). I think it would be
 acceptable to throw an exception if the data content of the source was
 malformed, but an empty set could simply indicate optional data that is
 not present.

 I'm a fairly new user of Boost, so if there is an alternative method for
 iterating over child trees in a more iterator-compliant manner, I
 apologize for the disruption (although if this is the case, the
 documentation probably needs to be updated).

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8465>
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