IMO it would seem reasonable and useful to 'support' NaN.
(If you mean that an interval cannot be bounded by a NaN, and a NaN cannot be contained by any set?)
Yes, this is exactly what I had in mind. I'm sure data sets with invalid data points are fairly common across many domains, particularly in cases where measurements are involved such as scientific data.
But the library author is 'in charge' and Joachim obviously thinks it would be too complicated to do this, so probably we have to accept that for now.
Understood and agreed, I'm simply trying to facilitate discussion since it seemed like an interesting and fairly reasonable use case.
The now-standard since tr1 isnan() function will help portability.
Perhaps if you can provide patches to deal with NaN, and some additional Boost-style tests, (and some 'patches' to the docs) you might change his mind?
Paul