溢出運(yùn)算符(Overflow Operator) 運(yùn)算符重載(Operator Overload) Equatable Comparable 自定義運(yùn)算符(Custom Operator) Apple文檔參考: https://developer.apple.com/documentation/swift/swift_standard_library/operator_declarations https://docs.swift.org/swiftbook/ReferenceManual/Declarations.html#ID380