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