Binary Conversion IO

[Paolo Carlini]

Hi Ed,

a big problem I can see with this kind of experimentation, is that for 
the time being we can't break the ABI, in the strong sense that 
interoperation between objects must also work (not just in terms of .so 
exports). As a frequent contributor you know what I mean. Now, as soon 
as you start fiddling with enums without paying *a lot* of attention, 
like changing values of enumerators, adding new enumerators in the 
middle, and so on, I think the game is already over. Adding at the end + 
double checking that the underlying type remains the same, normally 
should be safe, something which could be at least attempted, anyway. 
What do you think? Next step would be making sure that in strict 
-std=c++98 and -std=c++11 modes, we don't end up parsing something in a 
different way, etc, actually enabling the code only for -std=c++1y 
should be ok.

Thanks,
Paolo.