Re: [boost] [review] Multiprecision review (June 8th - 17th, 2012)

Subject: Re: [boost] [review] Multiprecision review (June 8th - 17th, 2012)
From: John Maddock (boost.regex_at_[hidden])
Date: 2012-06-24 07:25:54

Many thanks for the review,

>1) Introduction : I would prefer to see e.g. mp::int128_t rather than
>mp::mp_int128_t, given the stated purpose of the library.

OK.

>2) cpp_dec_float : Narrowing conversions are truncating.   This is a no-no
>for the usage I have in mind at the moment.

I know, it's something we need to at least try and fix.

>3) Constructing and interconverting :

>> // There is a need to be careful with integer types though:
>> cpp_int i = 2;
>> // Ooops, this really just multiplies by 3:
>> i *= 3.14;

>One of the priorities for my numeric class implementations has always been
>to protect naive users from equivalent mistakes.

Nod.

We have a request already for these conversions to be explicit, the next 
step is to try and disallow the operator overloads (enable_if) for narrowing 
conversions.

>I have started to use the library to embed test code for my special
>purpose decimal fixed point classes into an  application under development.
>The only issue, using VS2008 /W4 and Boost 1.48, was the need to
>disable warning 4996.

Nod.  We only use C++ std lib functions, but MS in their wisdom have 
"depricated" some of them :-(

Thanks again, John.