#1,055 – Defining Your Own Implicit Conversions

Suppose that you define a new value type, for example the TimedInteger type shown below.

    public struct TimedInteger
    {
        private int theInt;
        private DateTime whenCreated;

        public TimedInteger(int value)
        {
            theInt = value;
            whenCreated = DateTime.Now;
        }
    }

You can now create instances of this type as follows:

            TimedInteger ti = new TimedInteger(5);

You can’t directly assign an integer to a variable of type TimedInteger because no implicit conversion exists between an integer literal and your type.  (Between an int and your type).

To allow this assignment, you can define a custom implicit conversion for your type.  The code below allows an implicit conversion from an int to a TimedInteger.

        public static implicit operator TimedInteger(int value)
        {
            return new TimedInteger(value);
        }

You can now directly assign an integer literal, because there is an implicit conversion between int and TimedInteger.

            TimedInteger ti = 5;