8153386397
This now guarantees that doing a round-trip from an FP number to string and back to number results in the same number. This change is required because DBL_DIG and FLT_DIG don't have the meaning that we were expecting them to, here: they mean the minimum number of digits of precision in decimal (i.e., changing the last decimal will always cause the FP number to change). We need the maximum number: there is one change in the last decimal place that causes the FP number to change. IEEE 754 single-precision has 24 binary digits and double precision has 53 binary digits in their mantissa. To convert that to decimal, multiply by the number of decimal digits a binary digit represents (log2(10) = 0.3), then add one for the rounding and one more digit for the actual precision we want. That is, for floats we now ask for 9 digits and for double, 17 decimal digits. Task-number: QTBUG-42574 Change-Id: Ic78beb60a218f75322f832d33d63fd84e7a65b65 Reviewed-by: Lars Knoll <lars.knoll@digia.com> Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com> |
||
|---|---|---|
| .. | ||
| stream | ||
| .gitignore | ||
| qvariant.pro | ||
| qvariant.qrc | ||
| tst_qvariant.cpp | ||