[Boost-bugs] [Boost C++ Libraries] #3519: It should be possible to use consts as external placeholder variables.

Subject: [Boost-bugs] [Boost C++ Libraries] #3519: It should be possible to use consts as external placeholder variables.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-10-12 15:26:05

#3519: It should be possible to use consts as external placeholder variables.
-----------------------------------+----------------------------------------
 Reporter:  ami.ganguli@…          |       Owner:  eric_niebler
     Type:  Feature Requests       |      Status:  new         
Milestone:  To Be Determined       |   Component:  xpressive   
  Version:  Boost 1.40.0           |    Severity:  Problem     
 Keywords:                         |  
-----------------------------------+----------------------------------------
 The right-and-side of placeholder let-expressions are not declared as
 const, so common use-cases like:


 {{{
 placeholder<int> _i;
 smatch what;
 what.let(_i = 1);
 }}}


 or:


 {{{
 placeholder<MyClass *> _p;
 smatch what;
 what.let(_p = this);
 }}}


 fail to compile.  It would be nice to have some way to specify a
 placeholder for non-mutable data.  Perhaps:


 {{{
 placeholder<int const> _i;
 }}}

 (suggested by Eric Niebler)

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3519>
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