How do you check for infinite and indeterminate values in C++?

Question

In my programs infinity usually arises when a value is divided by zero. I get indeterminate when I divide zero by zero. How do you check for infinite and indeterminate value

Answer 1

Although not strictly a part of C++03, if your compiler provides some of the new C99 features of the standard header file, then you may have access to the following "function-like macros": isfinite, isinf, isnan. If so, these would be the easiest and safest way to perform these checks.