[Boost-bugs] [Boost C++ Libraries] #2319: function::operator= should "move", copy assignment should have by-value argument

Subject: [Boost-bugs] [Boost C++ Libraries] #2319: function::operator= should "move", copy assignment should have by-value argument
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-09-11 16:11:22

#2319: function::operator= should "move", copy assignment should have by-value
argument
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 Reporter:  niels_dekker  |       Owner:  dgregor 
     Type:  Bugs          |      Status:  new     
Milestone:  Boost 1.37.0  |   Component:  function
  Version:  Boost 1.36.0  |    Severity:  Problem 
 Keywords:                |  
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 A few days ago, I added a comment to ticket #1910 (regarding
 function::swap), suggesting to have boost::function's assignment operators
 calling its new ''move_assign'' member function, instead of calling
 ''swap''. Doing so would significantly improve its performance.

 Now I think that function::operator= deserves its own ticket, especially
 because the ''copy assignment'' of boost::function can be improved even
 more, by having its argument passed ''by value'', instead of creating a
 copy of the argument inside the body of the function. Doing so would allow
 the compiler to do copy elision, when its argument is an rvalue. See also
 [http://lists.boost.org/Archives/boost/2008/09/142106.php Improving the
 assignment operators of various Boost types]

 So please consider the attached patch.

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/2319>
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