Type Property


The available number of fractional significand bits.


static var significandBitCount: Int { get }


For fixed-width floating-point types, this is the actual number of fractional significand bits.

For extensible floating-point types, significandBitCount should be the maximum allowed significand width (without counting any leading integral bit of the significand). If there is no upper limit, then significandBitCount should be Int.max.

Float80.significandBitCount is 63, even though 64 bits are used to store the significand in the memory representation of a Float80 instance. Unlike other floating-point types, the Float80 type explicitly stores the leading integral significand bit.


From Protocol