[swift-users] Decimal to Double?
jgroff at apple.com
Mon Nov 28 13:31:14 CST 2016
> On Nov 28, 2016, at 11:29 AM, David Sweeris <davesweeris at mac.com> wrote:
> Sent from my iPhone
>> On Nov 28, 2016, at 13:21, Joe Groff <jgroff at apple.com> wrote:
>> It really shouldn't be, since ExpressibleByFloatLiteral uses a binary float initial value and so doesn't guarantee decimal accuracy. I'd recommend using init(mantissa:exponent:isNegative:) instead, and minimizing any conversions between Double and Decimal.
> That's what I was worried about... What's the "correct" way to express a literal as a Decimal, then? Use a string literal, `"2.1"`, instead of a float literal, `2.1`?
That would certainly be more robust than using float literals, though probably slower than constructing from elements using the init(mantissa:exponent:isNegative:) initializer.
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