Re: [Boost-users] [phoenix] function with reference implementation

11 Sep 2010


      On 9/11/10 8:31 AM, alfC wrote:
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On Sep 10, 4:36 pm, Joel de Guzman  wrote:
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On 9/11/10 4:37 AM, alfC wrote:
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I noticed that in some contexts I have both the object class and the
corresponding phoenix function
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class impl;
    ...
...
impl f_impl;
    boost::phoenix::function<impl>    f(f_impl);
...
now to avoid the copying I could use:
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boost::phoenix::function    f(f_impl);
...
which works. Although
    boost::phoenix::function    f(f_impl); //doesn't work.
(error below)
...
Is there any problem with using references at all, in the first place?
I'm not sure. Could you provide a minimal cpp file I can try?
Yes, see below. Althougth now that I made this example I realize that
the underlying object implementation is copied many times anyway (at
least 4 times in the example), I guess during the building up of the
expression template. [The final objective was to make an object
function that not only evaluates but also is able to take expression
and build expression templates].
Here's my suggestion: write a proxy function object that holds
the target function object by reference, pointer, or boost.ref
and use that to wrap your phoenix function.

HTH,

Regards,
-- 
Joel de Guzman
http://www.boostpro.com
http://spirit.sf.net