all,
try this and find the error
var valueRe:Float64 = 1.0
var valueIm:Float64 = -2.0
var results:DSPDoubleSplitComplex = DSPDoubleSplitComplex(realp: &valueRe, imagp: &valueIm)
var scalar:DSPDoubleSplitComplex = results
vDSP_zvfillD(&scalar, &results, 1, UInt(1) )
print(results.realp, results.imagp)answer
0x0000000113b5d838 0x0000000113b5d840