Type Property


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


static var significandBitCount: Int { get }


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.

Note that Float80.significandBitCount is 63, even though 64 bits are used to store the significand in the memory representation of a Float80 (unlike other floating-point types, Float80 explicitly stores the leading integral significand bit, but the BinaryFloatingPoint APIs provide an abstraction so that users don’t need to be aware of this detail).


From Protocol