[Cfp-interest 2406] Re: C++ and extended floating-point types

[David Olsen]

https://wg21.link/p1467 (Extended floating-point types) was discussed in CFP meetings a while back (I forget when), and in a joint CFP/SG22 (Liaison group) meeting last October.  This should not be completely new to CFP members.

>> Is this in the context of including in the currently active update to the C++ standard?

Yes, P1467 is on track to make it into C++23.  It has made it through both design groups, and is now being reviewed by both wording groups.

While the C and C++ approaches are very different, I have worked hard to keep them as compatible as is reasonably possible, so that it is relatively straightforward to write floating-point code that uses specific IEEE binary formats and that behaves the same in both languages.  I have made to changes to the C++ proposal to be more compatible with C, and I requested a couple changes to the C standard (though neither was ultimately adopted).

(Note that "extended floating-point type" has a completely different meaning in C++ than "extended floating type" does in C.  In C++, "extended floating-point type" just means a floating-point type other than float, double, or long double; the term comes from "extended integer type" which is already in the C++ standard.  P1467 is not adding support for the extended floating types _Float32x and _Float64x, though C++ implementations could provide those if they wish among their supported extended floating-point types.)


-----Original Message-----
From: Cfp-interest <cfp-interest-bounces at oakapple.net> On Behalf Of Damian McGuckin
Sent: Monday, March 21, 2022 8:58 AM
To: cfp-interest <cfp-interest at ucbtest.org>
Subject: [Cfp-interest 2400] Re: C++ and extended floating-point types



On Mon, 21 Mar 2022, Fred J. Tydeman wrote:

> It appears that C++ is looking into adding support for extended floating-point types:
>
> I have not (yet) read the paper, as I just found out about it.

Is this in the context of including in the currently actcive update to the
C++ standard?

Stay safe - Damian