近似相等

import ApproximateEquality
import ApproximateEqualityMacros
import CoreGraphics

@DeriveApproximateEquality
public struct MyType {
    var x: Double
    var y: CGPoint
    @ApproximateEqualityIgnored
    var z: Double
    var w: Float
}

let thing1 = MyType(x: 10, y: CGPoint(x: 20, y: 0), z: 30, w: 0)
let thing2 = MyType(x: 10, y: CGPoint(x: 20, y: 0), z: 40, w: 0)
let error = 0.000_001
let thing3 = MyType(x: 10 + error, y: CGPoint(x: 20, y: 0), z: 40, w: 0)

print(thing1.isApproximatelyEqual(to: thing2, absoluteTolerance: 0.0001))      // true
print(thing1.isApproximatelyEqual(to: thing3, absoluteTolerance: 0.0001))      // true
print(thing1.isApproximatelyEqual(to: thing3, absoluteTolerance: 0.000_000_1)) // false

extension MyType: ApproximateEquality {
    public func isApproximatelyEqual(to other: Self, absoluteTolerance: Double.Magnitude) -> Bool {
        x.isApproximatelyEqual(to: other.x, absoluteTolerance: Double.Magnitude(absoluteTolerance))
        && y.isApproximatelyEqual(to: other.y, absoluteTolerance: CGPoint.Magnitude(absoluteTolerance))
        && w.isApproximatelyEqual(to: other.w, absoluteTolerance: Float.Magnitude(absoluteTolerance))
    }
}