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Subject: Re: [boost] [Review Request] Multiprecision Arithmetic Library
From: Christopher Kormanyos (e_float_at_[hidden])
Date: 2012-04-07 19:51:13

<snip> > Ah, good point, oversight on my part.  I've just committed an update > that uses your 1100 digit values to initialize when possible. > John. Hi John, This caused a weird repercussion. When we define constants with hundreds or thousands of digits of precision in Boost.Multiprecision, this is in conflict with boost::math::constants, which has only tens or maybe a hundred digits. I instantiated an mp_number<cpp_dec_float> from the value of boost::math::constants::e() today and got only maybe 100 decimal digits of precision. This is a very subtle, hard to catch detail. It's easy to see in the source, but confusing when interacting with Boost.Multiprecision and Boost.Math. I don't know where to patch this one. Unfortunately, we might need to add more digits to Boost.Math. This seems to be string-based and can potentially be synchronized with our new 1100 digit strings.  Then we might want to consider a common string pool for Boost.Math and Boost.Multiprecision so as to avoid multiple upkeep of strings. Eventually, I will *hammer* Boost.Math with 1,000 digits. We will find issues. Best regards, Chris.

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