Re: [boost] Interest check: memoization

Subject: Re: [boost] Interest check: memoization
From: James Porter (porterj_at_[hidden])
Date: 2009-01-26 17:55:00

Mathias Gaunard wrote:
> Well, bind has an unspecified return type, and that never bothered anyone.
> If you don't have auto, just don't make it a named variable.

Since you generally want to store the memoizer somewhere (it's basically 
a container), this isn't always appropriate. However, I realized that 
for monomorphic function objects, I can just deduce the signature of 
operator() so that the memoizer's type is simply 
memoizer<my_function_object>.

> Can't you just do something like
[snip]

I'm intentionally avoiding (type-) polymorphic function objects (or 
rather, I'm restricting them to one overload), since knowing the exact 
function signature allows for better type-safety and, as Steven 
mentioned, eliminates the chance of creating spurious maps to store the 
memoized values.

I think the added restriction in terms of polymorphic function objects 
is worth the added safety with monomorphic types.

If you are interested in looking at the new code, I have updated source 
available here: http://www.teamboxel.com/misc/memoizer-0.2.tar.gz . 
There's obviously a lot of work left to do, but hopefully this will help 
resolve some of your questions regarding function objects.

- Jim