Re: [boost] Interest in static-sized valarray

From: Paul A Bristow (pbristow_at_[hidden])
Date: 2006-01-28 13:46:22

Sounds useful - if only to some people.

Paul -- 
Paul A Bristow
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| -----Original Message-----
| From: boost-bounces_at_[hidden] 
| [mailto:boost-bounces_at_[hidden]] On Behalf Of Michael Tegtmeyer
| Sent: 27 January 2006 19:40
| To: boost_at_[hidden]
| Subject: [boost] Interest in static-sized valarray
| 
| Hello,
| 
| I am trying to guage interest in a fixed sized version of valarray. I
| frequently found myself using small(-ish) compile-time known sized
| numeric arrays that don't justify the overhead of operator new in
| std::valarray but needed the math interface that valarray provided. I
| wrote a static-sized version of valarray for this purpose. It 
| is modeled
| after std::valarray and implements about 90% of valarray's interface
| (obviously resizing is not included, neither is gslice due to 
| the result
| not being known at compile time). Examples of it's use are:
| 
| float _v[10] = {...};
| size_t _i[5] = {...};
| 
| cvalarray<float,10> v1(_v);
| cvalarray<float,5> v2 = v1[cslice<0,5,2>()];
| v1[cslice<0,3,3>()] = 0.0f;
| 
| cvalarray<size_t,5> ind(_i);
| cvalarray<float,5> cvalB = v1[ind];
| 
| v2 *= (v2 + v1) / 2.0;
| //all of the usual math ops
| 
| I have a complete implementation that models std::valarray in every
| possible way (with compile-time known limitations) including
| expression-template support for the numeric ops. My testing 
| indicates a
| decent performance increase over gcc4's valarray for small number of
| elements <1000.
| 
| If anyone has any interest, I'll put together some docs and 
| throw it in
| the sandbox.
| 
| Mike Tegtmeyer
| 
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