Re: [Boost-bugs] [Boost C++ Libraries] #3395: Assignment to optional is not possible if operator& is overriden

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3395: Assignment to optional is not possible if operator& is overriden
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-09-03 07:02:43

#3395: Assignment to optional is not possible if operator& is overriden
---------------------------------+------------------------------------------
 Reporter:  andysem              |       Owner:  fcacciola
     Type:  Bugs                 |      Status:  new      
Milestone:  Boost 1.41.0         |   Component:  optional 
  Version:  Boost 1.40.0         |    Severity:  Problem  
 Keywords:  optional assignment  |  
---------------------------------+------------------------------------------

Comment(by andysem):

 BTW, I just now noticed that the assignment operator accepts its argument
 by value. It may be worth to accept it by const reference, as the operator
 is not only called for in-place factories but also for other types. For
 example:

 {{{
 struct MyString
 {
     MyString(std::string const&);
 };

 std::string str = "Hello";
 boost::optional< MyString > opt;

 opt = str; // here a needless copy of str will be constructed
 }}}

 I'm attaching an updated patch that fixes this, too.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3395#comment:1>
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