Portability of binary serialization of double/float type in C++

Question

The C++ standard does not discuss the underlying layout of float and double types, only the range of values they should represent. (This is also true for signed types, is i

Answer 1

I think the answer "depends" on what your particular application and it's perfomance profile is.

Let's say you have a low-latency market data environment, then using strings is frankly daft. If the information you are conveying is prices, then doubles (and binary representation of them) really are tricky to work with. Where as, if you don't really care about performance, and what you want is visibility (storage, transmission), then strings are an ideal candidate.

I would actually opt for integral mantissa/exponent representation of floats/doubles - i.e. at the earliest opportunity, convert the float/double to a pair of integers and then transmit that. You then only have to worry about the portability of integers and well, various routines (such as the hton() routines to handle conversions for you). Also store everything in your most prevalent platform's endianess (for example if you're only using linux, then what's the point of storing stuff in big endian?)