How to convert NSDecimalNumber to double
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I have a value being stored as an NSDecimalNumber and when I convert it to a double it's losing precision.

For the current piece of data I'm debugging against, the value is 0.2676655. When I send it a doubleValue message, I get 0.267665. It's truncating instead of rounding and this is wreaking havoc with some code that uses hashes to detect data changes for a syncing operation.

The NSDecimalNumber instance comes from a third-party framework so I can't just replace it with a primitive double. Ultimately it gets inserted into an NSMutableString so I'm after a string representation, however it needs to be passed through a format specifier of "%.6lf", basically I need six digits after the decimal so it looks like 0.267666.

How can I accomplish this without losing precision? If there's a good way to format the NSDecimalNumber without converting to a double that will work as well.