Proto for Boost mailing list page: Re: [proto] Precomputing common matrix products in an expression

Subject: Re: [proto] Precomputing common matrix products in an expression
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2012-07-15 04:44:49

On 07/15/2012 10:25 AM, Bart Janssens wrote:

> OK, thanks for the comments. It's similar to what I had in mind, but
> (unless I'm missing something) all product terms in our expressions
> should have a distinct type if they represent different values, so I
> could get away with just using a fusion map and avoid the copying and
> even the map lookup.

In which case, you can replace the std::map<Expr, result_type> by a 
boost::optional<result_type>.