[Cfp-interest] printf flag character for NaNs

[Fred J. Tydeman]

On Wed, 13 Apr 2011 16:46:15 -0700 (PDT) David Hough CFP wrote:
>
>Last time we wondered about using a flag character to modify the output
>treatment of NaNs (we could also use it to modify scanf input treatment 
>if needed).

I missed that and the minutes also missed that discussion.

>The standard flag characters -+#0 and space already have semantics for
>floating-point output that we don't want to overlay with NaN semantics.

While # has semantics for a,A,e,E,f,F,g,G, it only affects finite numbers.
We could use it to force printing payload of NaNs.  Since # means use
an "alternative form", it makes perfect sense for NaN payloads.

---
Fred J. Tydeman        Tydeman Consulting
tydeman at tybor.com      Testing, numerics, programming
+1 (775) 358-9748      Vice-chair of PL22.11 (ANSI "C")
Sample C99+FPCE tests: http://www.tybor.com
Savers sleep well, investors eat well, spenders work forever.