Re: Re: Preprocessor library question

From: Paul Mensonides (yg-boost-users_at_[hidden])
Date: 2002-12-19 21:28:05

----- Original Message -----
From: "Tanton Gibbs" <thgibbs_at_[hidden]>

> Thanks for your response, I'll look through it and try to get a full grasp
> on everything you said.

No problem.  Basically it just uses nested switch statements to bind a
single value to a compile-time value.  But, as I mentioned, this is going to
go through the roof with instantiations real quick--especially at 101^3.

> Basically, my problem is this
>
> I have to read in a file of fixed length records, manipulate them (e.g.,
> sort, dedup, group, some custom processing ) and then write them out.
There
> are about 40M records, so I want it to be as fast as possible.  If I know
> the length of the record fields ahead of time, it is MUCH more efficient.
> However, I would like the field lengths to be customizable at runtime...I
> thought if I could precompute the program for various values of the 3
> fields, then I could have the best of both worlds.  However, I forgot
about
> all the template instantiations...perhaps they'll just have to recompile
> when they want a new field length.

Are all the record lengths constant at any given time?

Paul Mensonides