[boost] [Soc 07] BigInt Alternate Projects -- SOC BigInt applicants please read!

From: Jeff Garland (jeff_at_[hidden])
Date: 2007-03-25 20:51:35

Hi All -

We've had a ton of BigInt (I'd guess ~40) proposals for SoC.  This is 
really unfortunate because some good students are going to get left out 
-- we're only going to accept one. We've already been warning folks, but 
to help just a bit more, I've come up with a couple of alternatives that 
are closely related to BigInt, but a bit different.  This way we might 
improve things just a bit.

So, everyone that's applied for BigInt that might be interested in doing 
one of these other 2 projects, please do the following:
   a) make a comment on your application that indicates you are 
interested in doing one of these others
   b) or, send an email to soc_mentors2007-at-crystalclearsoftware.com 
indicating this fact
   c) Write a new proposal before the deadline

Obviously C is the best, but I realize time is short before the deadline 
-- and I know the Google server has been timing out, so I'm trying to 
make this as fair as possible.  If your application is sketchier, we'll 
understand because it's short notice and we will work with the leading 
candidates after the deadline to refine the application.

If you really prefer to do one of the new projects feel free to withdraw 
your BigInt application.  However, if you leave it we will continue to 
consider that your first choice unless you indicate otherwise.

Below is the text I've added to the Wiki.

Thx,

Jeff

---------------------------
Safe Integer

Introduction: Implement 'safe int' class template which supports all C++ 
arithmetic and boolean operators and will ensure client notification on 
all failures such as arithmetic overflow and underflow.

Goal: Platform independent code, docs and tests to Boost need to be 
delivered -- review within SoC? period would be a plus (only if you 
think it's doable).

Requirements: Basic knowledge of C++ templates and a good understanding 
of limits of computer computation systems. Extreme ability to focus on 
details.

Notes: The target here is to applications that are highlh David LeBlanc? 
at Microsoft created something similar a couple years back. See 
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dncode/html/secure01142004.asp

SafeInt and suggest might be combined with existing Boost code from 
date_time call constrained_value. this would allow you to define 
constrained range safe integers like this:

     typedef SafeInt?<int, 0, 255> BufRange?;
     char buf[BufRange?::max()+1];
     BufRange? i = 254;
     i++;   //ok
     i++;   //out of range exception
    //now it's impossible for this to be out of range:
    if (buf[i] == ...

---------------------------
Fixed Decimal

Introduction: Fixed Decimal types provide an alternative to floating 
point types that are superior in their calculation properties. Robert 
Klarer of IBM has proposed adding these types to C++ [in n2198 (pdf)] 
and prior papers. This work is now on track to be included in C++0x. 
Robert has an implementation of these types with a restrained license. 
This project involves implementing the n2198 interfaces in a Boost library.

Goal: Platform independent code, docs and tests to Boost need to be 
delivered with as much of 2198 as possible.

Requirements: Basic knowledge of C++ templates and a good understanding 
of limits of computer computation systems. Extreme ability to focus on 
details.

Notes: This project clearly involves much less 'interface design' since 
the interface is already defined. However there is still tricky design 
work to implement these types correctly. Some research on the best 
approaches might be required.