Andrea Denzler wrote:
Most modern platforms use the IEEE 754 (1985) encoding for binary data (float/double). But I suppose there is still the (easy to handle) endianess issue. http://www.appinf.com/download/FPIssues.pdf
and how would I go about handling the endianness issue? is there a compile-time define in boost already that signals endianness of floating point types? or is the endiannes of the floating point types the very same as for integer types? I was looking at the implementation of the Qt class QDataStream, which serves a similar purpose. What they simply do is that they store the 4 bytes for floats in big endian order (swap if the system is little endian). for doubles, they have a more elaborate mapping, handling four cases: - normal little endian format - swapped little endian format - normal big endian format - swapped big endian format their test is rather simple - they take a number that has a double representation equivalent of the character array: "0123ABCD0123ABCD\0\0\0\0\0\0\0" in normal little endian format, and then use the pattern resulting on the target system to determine the format of the system itself. but this has to be done at compile time. my question is: is there some similar, compile / configure time test for boost available already, which result I could use to add float and double support to the portable_binary_archive class, thus making it complete? or do I have to implement my own tests for this purpose? (this would add complexity to my project, as so far I myself don't have configure-time tests at all, but depend on boost and similar libraries to already provide me with target platform details). Akos