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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

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