V3 PATCH: numeric_limits<> support, fix PR/3865

[Gabriel Dos Reis]

Roger Sayle <roger@eyesopen.com> writes:

| Hi Richard,
| 
| > I suppose we could define "snan" (case insensitive) to do what we
| > want.  I'd bet that Uli would be willing to pick this up for glibc's
| > strtod implementation.  We'd probably be "inconsistent" with other
| > libcs, but in an extremely minor way.
| 
| I believe a relevant document might be N965 "Optional support for
| Signaling NaNs" from WG14.
| 
| http://std.dkuug.dk/JTC1/SC22/WG14/www/docs/n965.htm
| 
| In this draft, the suggested extension to strtod is to use "NANS"
| rather than "snan" (as proposed by RTH).

This is rather surprising, as in the literature, the common practice is
QNaN and SNaN.  See writings of Kahan for example.


-- Gaby