<p>I am looking for suggestions on how to find the sizes (in bits) and range of floating point numbers in an architecture independent manner.  The code could be built on various platforms (AIX, Linux, HPUX, VMS, maybe Windoze) using different flags - so results should vary.  The sign, I've only seen as one bit, but how to measure the size of the exponent and mantissa?</p>

Have a look at the values defined in
```
float.h
```
. Those should give you the values you need.