     return lhs
 }
 
-public func -=(inout lhs: Decimal, rhs: Decimal) -> Decimal {
+public func -=(inout lhs: Decimal, rhs: Decimal) {
     lhs = Decimal(lhs.value.decimalNumberBySubtracting(rhs.value))
-    return lhs
-}
-
-public func -=(inout lhs: Decimal, rhs: Int) -> Decimal {
+}
+
+public func -=(inout lhs: Decimal, rhs: Int) {
     lhs = Decimal(lhs.value.decimalNumberBySubtracting(NSDecimalNumber(integer: rhs)))
-    return lhs
-}
-
-public func -=(inout lhs: Decimal, rhs: Double) -> Decimal {
+}
+
+public func -=(inout lhs: Decimal, rhs: Double) {
     lhs = Decimal(lhs.value.decimalNumberBySubtracting(NSDecimalNumber(double: rhs)))
-    return lhs
 }
 
 

    return Decimal(lhs.value.decimalNumberByDividingBy(rhs.value))
}

public func /=(inout lhs: Decimal, rhs: Decimal) -> Decimal {
    lhs = Decimal(lhs.value.decimalNumberByDividingBy(rhs.value))
    return lhs
}

public func /=(inout lhs: Decimal, rhs: Int) -> Decimal {
    lhs = Decimal(lhs.value.decimalNumberByDividingBy(NSDecimalNumber(integer: rhs)))
    return lhs
}

public func /=(inout lhs: Decimal, rhs: Double) -> Decimal {
    lhs = Decimal(lhs.value.decimalNumberByDividingBy(NSDecimalNumber(double: rhs)))
    return lhs
}

// MARK: Power-of operators

    return lhs
}

public func +=(inout lhs: Decimal, rhs: Decimal) {
    lhs = Decimal(lhs.value.decimalNumberByAdding(rhs.value))
}

public func +=(inout lhs: Decimal, rhs: Int) {
    lhs = Decimal(lhs.value.decimalNumberByAdding(NSDecimalNumber(integer: rhs)))
}

public func +=(inout lhs: Decimal, rhs: Double) {
    lhs = Decimal(lhs.value.decimalNumberByAdding(NSDecimalNumber(double: rhs)))
}

// MARK: Subtraction operators
