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From: Anthony Williams (anthony_w.geo_at_[hidden])
Date: 2007-04-27 11:20:37

"Phil Endecott" <spam_from_boost_dev_at_[hidden]> writes:

> Last week I posted some fixed-point arithmetic code for potential
> boostification. Thanks for all your comments.

> - The need for <cmath>-like functions. This is rather beyond my ability.

I've just implemented some 64-bit (35.28, signed) fixed-point math functions:
exp, sqrt, sin, cos. I can post the code if you like.

> - What implicit and/or explicit conversions should be included?

I've got implicit (and explicit) conversions to/from every built-in arithmetic

> I look forward to hearing your comments. I'm keen to maintain
> momentum; if people think that something not too different in scope
> from what I am currently proposing would be acceptable then I will
> start thinking about the other things that are needed (docs, tests etc).

I like the ability to specify the number of bits either side of the decimal
point, but this does get in the way for doing the math functions --- you need
a table with magic numbers in at the appropriate precision for exp and


Anthony Williams
Just Software Solutions Ltd -
Registered in England, Company Number 5478976.
Registered Office: 15 Carrallack Mews, St Just, Cornwall, TR19 7UL

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