Re: [Boost-bugs] [Boost C++ Libraries] #5096: display_expr is noncopyable

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #5096: display_expr is noncopyable
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-01-22 21:13:56

#5096: display_expr is noncopyable
  Reporter: cschmidt | Owner: eric_niebler
      Type: Bugs | Status: closed
 Milestone: To Be Determined | Component: proto
   Version: Boost Development Trunk | Severity: Problem
Resolution: fixed | Keywords:

Comment (by cschmidt):

 Strictly speaking, [68314] defers the problem to
 detail::display_expr_impl, which is passed to fusion::for_each in
 display_expr_impl::impl although it is noncopyable. This is fine for now
 as Fusion passes around functors by const reference although the
 documentation states the opposite.

 AFAIK Fusion's current implementation is plain wrong. Functors should
 never be passed around by const reference. IIRC that's due to a defect in

 Anyway, wontfix/invalid is fine for me for now. I will try to propose a
 patch for fusion that removes const/reference qualifiers on functors and
 adds support for reference wrappers.

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