John Maddock wrote:
Ah, I think there are still 2 bugs:
* There's no special handling for long double - so it gets the default 5 digits.
easy to fix. Post a ticket.
* You don't output in scientific format: what that means in practice is that if you write a number with a small exponent and it gets printed in fixed format, then you get std::numeric_limits<float>::digits10 + 2 digits *after the decimal point*. That may be too many digits if the exponent is > 0, but if the exponent is < 0 then you get fewer *significant* digits printed than you might expect, as the number will be 0.001234.... etc
hmmm section 18.3.2.4 of the standards says: static constexpr int digits10; 11 Number of base 10 digits that can be represented without change.198 12 Meaningful for all specializations in which is_bounded != false. static constexpr int max_digits10; 13 Number of base 10 digits required to ensure that values which differ are always differentiated. 14 Meaningful for all floating point types. So I don't read this as number of digits to the right of the decimal point. I take it to be number of significant digits which is not the same to me. But maybe it is. In anycase it looks like I should be using max_digits10 instead of digits10+2 in anycase. So this definitely should be looked into.
And of course there's still no way to set the number of digits on UDT's declared as primitives.
hmmm - since you have to implement them yourself, you can do it anyway you want.
PS would it be OK to apply the patch from https://svn.boost.org/trac/boost/ticket/8963 ?
feel free. Currently my development system is in ... err a state of flux so I can't really patch/test the library. Robert Ramey