Re: [boost] Math tools polynomial enhancements

Subject: Re: [boost] Math tools polynomial enhancements
From: Robert Ramey (ramey_at_[hidden])
Date: 2015-10-30 17:16:24

On 10/30/15 10:53 AM, John Maddock wrote:

> I suspect the explosion of template instances for any non-trivial uses
> would also explode compile times?

I confess that I never worry about this.  I see this concern raised all 
the time but I never notice it in my own work.  One thing I do to is 
avoid the "convenience" headers and include only the headers I actually 
know I need so maybe that helps.  Also for the serialization library I 
use make a library component - maybe that speeds up the build of all the 
applications.  also CMake and B2 only recompile changed stuff, so that 
seems to help also. Anyway - for me this doesn't ever seem a real 
problem - especially these days.

> Of course C++17 may (or not) fix both of the above.
>
> A simpler alternative might be:
>
> template <class T, size_t N>
> class polynomial;
>
> Which implements a polynomial of maximum order N.  Multiplication would
> have to be mod x^N as I can't think of an error handling mechanism that
> works for both runtime and constexpr contexts?

Well, I'm not seeing any of this.  If I multiply a polynomial of order N 
and one of order M, I'm going to get a resultant polynomial of order M + 
N, am I not?  Similarly with division I'll get one of M - N (ignoring 
the admittedly sticky question of the remainder.

And what kind of error could mulitplication of polynomials give?

I must say I'm quite intrigued with this for C++ 14.  I can't justify 
spending any time on it though.

Robert Ramey