Re: [boost] Re: Re: is_nan

From: Gabriel Dos Reis (gdr_at_[hidden])
Date: 2003-07-13 03:15:48

"Fernando Cacciola" <fcacciola_at_[hidden]> writes:

[...]

| > > Most compilers provide a non standard extension for this purpose.
| > > For instance, Borland uses _isnan.
| > > In general, these extensions are found on <float>.
| >
| > In fact, since it is not specified by the C++ standard, isnan comes from
| > the C headers and is supposed to be found in <math.h>.
| >
| Right.. I was actually thinking on the C header but wrote it incorrectly.
| I meant <cfloat>.

I would like to point out that a correct implementation of isnan would

  1) use a reference to its parameter
  2) rely on compiler extension.

(I'll try to get built-in support for isnan in GCC).

-- Gaby