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Task/Arithmetic-Complex/Swift/arithmetic-complex-1.swift

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+public struct Complex {
+
+    public let real : Double
+    public let imaginary : Double
+
+    public init(real inReal:Double, imaginary inImaginary:Double) {
+        real = inReal
+        imaginary = inImaginary
+    }
+
+    public static var i : Complex = Complex(real:0, imaginary: 1)
+    public static var zero : Complex = Complex(real: 0, imaginary: 0)
+
+    public var negate : Complex {
+        return Complex(real: -real, imaginary: -imaginary)
+    }
+
+    public var invert : Complex {
+        let d = (real*real + imaginary*imaginary)
+        return Complex(real: real/d, imaginary: -imaginary/d)
+    }
+
+    public var conjugate : Complex {
+        return Complex(real: real, imaginary: -imaginary)
+    }
+
+}
+public func + (left: Complex, right: Complex) -> Complex {
+
+    return Complex(real: left.real+right.real, imaginary: left.imaginary+right.imaginary)
+}
+public func * (left: Complex, right: Complex) -> Complex {
+
+    return Complex(real: left.real*right.real - left.imaginary*right.imaginary,
+        imaginary: left.real*right.imaginary+left.imaginary*right.real)
+}
+public prefix func - (right:Complex) -> Complex {
+    return right.negate
+}
+
+// Checking equality is almost necessary for a struct of this type  to be useful
+extension Complex : Equatable {}
+public func == (left:Complex, right:Complex) -> Bool {
+    return left.real == right.real && left.imaginary == right.imaginary
+}