A first draft of this library is available at https://sourceforge.net/projects/stddecimal/ Runs on MSVC10 and gcc 4.6.3.
Wraps the Intel implementation only, In my opinion, this is a good start. But to really improve the
Until we resolve the licencing issue, top-level README contains detailed instructions about where to get 3rd party code and what to do with it. As far as I know, you simply won't get the third party code into boost. Perhaps I'm wrong here. But the best you can do is create a front end C++ implementation in as portable a way as possible and
OK, Josh. Sorry I have not weighed in on this interesting proposal until now. I have included some very detailed comments below. portability and usefulness of your proposal, you might want to consider writing your own portable decimal back end. provide a mechanism for linking with prebuilt versions of the 3rd-party library. This is, for example, what we have done with GNU GMP, MPFR and MPIR in association with the proposed Boost.Multiprecision library.
I'm keen on feedback on a particular point (although all feedback is of course welcome!):
So... what do people think? Regards, Josh.
Josh, I believe you have made a good start. But as mentioned above, a boost decimal implementation really would, in my opinion, mandate a fully portable boost-owned decimal back end. It looks like we are entering, well, a very *numeric* time at boost. Just take a look at the review schedule. We've got quaternions, multiprecision, complex numbers and there has been recent interest in creating a potential boost fixed-point implementation. It only makes sense to consider a decimal implementation. But we would need to figure out how this would best fit into the existing (and potentially future) numerical context of boost. I know, you can never please all the people all the time. But from a guy who has written numerous custom number back ends, here's what I would suggest: 1) Consider writing your own fully portable, boost-owned decimal. Provide the Intel compatibility as an optimized back-end for selected architecture. You would need a bit more software architecture to support multiple back ends. 2) I'm probably jumping the gun here, but you may want to take a look at the back-end requirements for a number type in the proposed Boost.Multiprecision. You might eventually want to target compatibility with this potential boost library. 3) You have some amounts of code in cpp source files. In my opinion, a decimal implementation should be header-only. The one exception is the use of library code mentioned earlier. One of the powers of boost is its portability. And this is strongly facilitated with its emphasis on header-only libraries. 4) Is there any connection between decimal and fixed-point? If so, do you want to contact Vicente Escriba who is concerned with fixed-point? 5) Do you need any elementary transcendental functions such as sin, cos, tan, exp, log, etc. Do you want to support any of these? Do your potential users need them? If so, I could potentially point you in the right direction for getting started on some potentially sensible algorithms in the digit ranges you are targeting. Again, to iterate lika a broken record... Why don't you make a first attempt at writing the code for the *guts* of the decimal types. I would be in a position to assist you with this, if you would like. However, I will be available at the earliest in fall for any significant contribution on a project with this level of complexity. Good luck on this interesting project. Best regards, Chris.