[Boost-bugs] [Boost C++ Libraries] #4020: regex::match_results::format functor cannot use member variables

Subject: [Boost-bugs] [Boost C++ Libraries] #4020: regex::match_results::format functor cannot use member variables
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-03-16 18:33:21

#4020: regex::match_results::format  functor cannot use member variables
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 Reporter:  Keith MacDonald <keith@…>            |       Owner:  johnmaddock
     Type:  Support Requests                     |      Status:  new        
Milestone:  Boost 1.43.0                         |   Component:  regex      
  Version:  Boost 1.42.0                         |    Severity:  Problem    
 Keywords:  regex functor                        |  
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 regex::match_results::format makes a copy of its functor argument.  This
 is restrictive, because it prevents the functor from managing its state
 using member variables.  Is that intentional?

 The attached VC++ 2008 code demonstrates the problem.  When it uses a
 member variable to maintain a count, its output is:

 (1)The (1)quick (1)brown (1)fox (1)jumped (1)over (1)the (1)lazy (1)dog

 Making the counter global instead gives the correct output:

 (1)The (2)quick (3)brown (4)fox (5)jumped (6)over (7)the (8)lazy (9)dog

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/4020>
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