class C1
{
    // CA1822 Member 'op_Increment' does not access instance data and can be marked as static
    public void operator ++() 
    {
    }

    // CA1822 Member 'op_SubtractionAssignment' does not access instance data and can be marked as static
    // IDE0060 Remove unused parameter 'i'
    public void operator -=(int i)
    {
    }
}