[boost] [ICL] #6853: boost::icl::contains(NaN) returns true

Subject: [boost] [ICL] #6853: boost::icl::contains(NaN) returns true
From: Andrew Hundt (ahundt_at_[hidden])
Date: 2012-05-04 11:14:27

I had submitted a bug report for icl, and the response I included below
seemed indicate this is more for the list than a bug report. It deals with
an issue where boost::icl::contains(NaN) returns true, where any NaN value
cannot actually be contained within an interval, and so should return false.

I'm dealing with data that comes from a physical device, so each
measurement the system returns is not guaranteed to be valid. We set those
invalid measurements to NaN. However, when the data is valid it falls into
certain intervals that I found icl well suited for, despite not falling
into the original use case of time scheduling I find it to be a reasonable
representation to work with. While IEEE floating point numbers is not
required by the C++ standard, it is a standard that does seem to have
fairly wide use in C++.

It seems, at least in my use case, that NaN is a very reasonable value to
use and fits well with the functionality icl provides. However, I wanted to
open this to wider opinions to learn about the state of the issue.

Cheers!
Andrew Hundt

---------- Forwarded message ----------
From: Boost C++ Libraries <noreply_at_[hidden]>
Date: Fri, May 4, 2012 at 6:50 AM
Subject: Re: [Boost C++ Libraries] #6853: [ICL] boost::icl::contains(NaN)
returns true
To:
Cc: boost-bugs_at_[hidden]

#6853: [ICL] boost::icl::contains(NaN) returns true
-----------------------------------------------+----------------------------
  Reporter:  Andrew Hundt <ATHundt@…>          |       Owner:  jofaber
      Type:  Bugs                              |      Status:  closed
 Milestone:  To Be Determined                  |   Component:  ICL
  Version:  Boost 1.49.0                      |    Severity:  Problem
Resolution:  invalid                           |    Keywords:  icl
-----------------------------------------------+----------------------------
Changes (by jofaber):

 * status:  new => closed
 * resolution:  => invalid

Comment:

 Hi Andrew,

 icl code is not intended to be NaN complete. NaN is a weird animal that
 breaks concepts the icl is based on. Completing icl for NaN would make the
 code unnecessarily clumsy for cases that are hardly ever used. If you
 desire to complete your code for NaN cases you will have to do it in your
 code or write your own NaN layer around the icl.

 Regards,
 Joachim

--
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6853#comment:1>
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