Proto for Boost mailing list page: Re: [proto] Manipulating an expression tree

Subject: Re: [proto] Manipulating an expression tree
From: Bart Janssens (bart.janssens_at_[hidden])
Date: 2011-04-08 08:16:47

On Fri, Apr 8, 2011 at 2:11 PM, Karsten Ahnert
<karsten.ahnert_at_[hidden]> wrote:
> Thank you for your example. I have one question: how do you use (or assign
> something to) the intermediate values in StoredMatrixExpression?

Once the wrapping is done, every wrapped node (multiplies expressions
in your case) will have the "value" member. This can be used from
within any primitive transform or context, if you are working on the
expression after it is transformed by WrapExpression. So instead of
eval(your_expr) you would do something like
eval(WrapExpression()(your_expr)) and then you can assume value exists
when it is needed.

Cheers,

-- 
Bart