-(_:_:)
Generates a column by subtracting each element in a column type from the corresponding elements of an optional column.
Declaration
func - <L, R>(lhs: L, rhs: R) -> Column<R.Element> where L : OptionalColumnProtocol, R : ColumnProtocol, L.WrappedElement : AdditiveArithmetic, L.WrappedElement == R.ElementParameters
- lhs:
An optional column type.
- rhs:
A column type.
Return Value
A new column with the same type as the right column.