floating point invalid operation

[adamle]

Hey all,

Actually I have a problem while trying to check whether a pointer has +NaN or -NaN. Variable is defined as an extern float pointer. I have used x!=x, _isnan function and many more methods. All these methods raise an error saying floating point invalid operation. Please help me to solve this issue.

Example line where it raises an exception is:
bool nan = _isnan(x);

Environment: Embarcadero C++ builder XE2

Ashwini

[2kaud]

Variable is defined as an extern float pointer

if x is the pointer, then don't you mean

bool nan = isnan(*x);

Also why use _isnan()? Why not the c++ isnan() from <cmath> ? See http://www.cplusplus.com/reference/cmath/isnan/

[adamle]

Actually I am dereferencing the pointer in a for loop.
Also I am not able detect isnan() macro in <cmath> library

[VictorN]

Actually I am dereferencing the pointer in a for loop.
Also I am not able detect isnan() macro in <cmath> library

Why don't you want to show your actual code?

[2kaud]

Actually I am dereferencing the pointer in a for loop.
Also I am not able detect isnan() macro in <cmath> library

isnan() within <cmath> is part of the c++11 standard - so Builder XE2 mustn't be c++11 compliant. Have you considered upgrading to a c++11/14 compliant version/compiler?