GDB to detect NAN

[swagat]

Hi all!

I don't know if it is the right forum to ask for gdb problems. IF it is
not, please do let me know.

In my c++ program, a particular variable takes up "nan" value after
sometime. I want my program to stop executing at a line where it takes
up a NAN value.

How can I use GDB to perform this task?

When I use a command like

(gdb) break main.cpp:283 if x == nan
reakpoint 2 at 0x8049ff3: file main.cpp, line 283.
c
it continues the program and then gives out following message:

Error in testing breakpoint condition:
Invalid type combination in equality test.



Please help.


Regards,
swagat