Its an interesting point, and I was interested to see if the authors will make some strong case that decimal floating-point is needed in finance. Obviously, as you mention, if financial calculations are supposed to be rounded to cents at every stage, one could write the entire software operating with integers (cents), and only converting to dollars and cents at the report printing stage.
Similarly, in the bitcoin domain, AFAIK, transfers and accounting is supposed to be done not in floating point but in integer satoshi.
But should it be done this way or in floating decimals? Is it possible to emulate decimal fixed-point using decimal floating-point?
In Reuben's MySQL case that was previously answered I don't see any reason we can't replicate fixed-point. The general case would obviously be different but restricted subsets it's fine. We also have the rescale function you brought up in your pre-review comments.
The user guide is silent on any of these questions, so I have not been able to make up my mind if this library is needed or not in finance.
For general mathematical use, and any sort of scientitic calculations, I am now 100% convinced decimals must not be used.
The only other conceivable use, to write a spreadsheet and/or calculator software, but again there is nothing in the docs to inform us how is this supposed to be accomplished.
There are actually a few examples on financial calculations, since you asked for this in pre-reivew, that are discussed in the docs. This one even shows you how to parse and use CSV data since that's tied to calculations with your spreadsheets: https://github.com/cppalliance/decimal/blob/develop/examples/moving_average.... and this one shows you how to parse the CSV data and then leverage our designed integration with Boost.Math: https://github.com/cppalliance/decimal/blob/develop/examples/statistics.cpp Matt