Re: [Boost-users] [boost] Ann: Floating Point Utilities Reviewstarts today

From: Johan Råde (rade_at_[hidden])
Date: 2008-02-26 08:50:02

John Maddock wrote:
> Johan Råde wrote:
>> Could you check the value of ss.str() after line 105 in
>> legacy_test.cpp?
> 
> 1.#QNAN -1.#IND 1.#QNAN -1.#QNAN
> 
> With MSVC's debug checks enabled the attempt to read from the stream at line 
> 108 results in a debug assertion being triggered and the code aborting: it 
> tries to increment the istream_iterator past the end :-(

Can you check if it is reading b11 that causes problems in line 108:

     ss >> b1 >> b2 >> b3 >> b4 >> b5 >> b6 >> b7 >> b8 >> b9 >> b10 >> b11;

What happens if you change line 105 from

     ss << " qnan snan nanq nans 1.#IND 1.#QNAN 1.#SNAN";

to (note the space at the end of the string)

     ss << " qnan snan nanq nans 1.#IND 1.#QNAN 1.#SNAN ";

> 
> BTW both VC8 and VC9 express editions are free downloads from MS's web 
> pages.
> 
> Changing from -std::numeric_limits<>::whatever() to changesign(whatever) 
> fixes the SSE2 problem with VC8 and VC9 BTW, however this is probably best 
> considered either a compiler bug, or a loophole in the std if this is 
> permitted behaviour.

If I drop the support for signed NaN, then whis will become a non-issue anyway.

--Johan