How to check if C++ compiler uses IEEE 754 floatin

Question

I would like to ask a question that follows this one which is pretty well answered by the define check if the compiler uses the standard. However this woks for C only. Is there a way to do the same in C++?

I do not wish to covert floating point types to text or use some pretty complex conversion functions. I just need the compiler check. If you know a list of such compatible compilers please post the link. I could not find it.

Answer 1

Actually you have an easier way to achieve this in C++. From the C++ standard 18.2.1.1 the class numeric_limits exists within std. In order to access said static member you simply do this:

std::numeric_limits<double>::is_iec559;

Or:

std::numeric_limits<float>::is_iec559;

Which should return true if IEEE 754 is in use, false otherwise.

As an alternative method, the second part of Adam's answer should do it also for C++.

Answer 2

Although this post is a bit old (10 years), you could still try this. It also works in C:

#ifndef __STDC_IEC_559__
#error The following Programm only supports float operations using the IEEE 754 Standard
#endif