Hi Bill, Yes, 'precision' is what I meant. I used the term' digits' because that's what is used for 'numeric_limits<>', but I much prefer 'precision'. There is one thing I noticed though that I'd like you to confirm: Because of the implementation (a normalized rep with two separate int_type members), given 'M' as numeric_limits<int_type>::digits10, then the decimal 'precision' is M+1. If you look at the 'max values with different scales' output of my first post, you'll see that all values have 19 digits, while __int64 support 18 digits at most.
That is, numeric_limits<decimal>::digits = numeric_limits<decimal>::digits10 = numeric_limits<int_type>::digits10+1 > > I would say "digits to the right of the decimal point". (Digits > to the left of the point I would also call "decimal" because > they're base-10.) > Agreed. > > > > It cannot be > '(digits-1'), ... > > > > Yes, the scale can be equal to the precision (which I believe is > what you're calling "digits"); but then, in general, there won't be > any digits to the left of the point. > I tried to actually create a decimal with no whole digit to show the equality you mentioned above but failed. Could it be that because of the implementation there is always at least one whole digit? I think so, and in this case, the scale can be at most precision-1. > > > > If the concept of 'digits' is formalized, alon with its relation > > to 'scale', then this statement could simply say that "The conversion > > will be exact if the string contains no more than 'digits()' digits > > (whole and/or decimal)" > > > > I don't think that's right. I can assign 123.45 to a decimal with > a scale of 2 without rounding. As long as 'precision' is >= 5. > Do I misunderstand what you're saying? > No, the statement was not clear enough. What I meant is this: if the string contains a total of more than 'precision' digits, the representation won't be exact. In fact, it will have an implementation-defined value. So, I would leave the original sentence, and add a next sentence stating the above additional constrian. Fernando Cacciola _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
