[Rd] Standalone Mathlib, C++ and ISNAN()

Thomas Lumley tlumley at u.washington.edu
Wed Jan 5 20:53:29 CET 2005

On Thu, 6 Jan 2005, Bill Northcott wrote:

> As I explained in the last message:
>>> In R2.0 ISNAN() is defined using isnan thus (isnan(x)!=0).  isnan() is in 
>>> math.h and this works perfectly for C code.  However, in C++ the header 
>>> cmath (included by iostream and others) undefs isnan().  So on platforms 
>>> for which isnan() is a macro, the code breaks at compile time with 
>>> 'isnan() undeclared'.

I believe (with a little Googling) the suggested C++ approach is to use 
std::isnan if <cmath> is included.


Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle

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