Implicit and Explicit Operator in C#

One of the features that I have never used in C# is the implicit and Explicit keywords.

The definitive word from MSDN on explicit is "The explicit keyword declares a user-defined type conversion operator that must be invoked with a cast." Omitting the cast will result in a compile time warning.

The definitive word from MSDN on implicit is "The implicit keyword is used to declare an implicit user-defined type conversion operator." Implicit doesn't require an explicit cast and makes the syntax a lot easier.

public class Program
{
    public static void Main()
    {

    Email test = "alice@test.com";
    System.Console.WriteLine("Test: " + test);        
    }
}

class Email
    {
        private string user;
        private string domain;
        public Email(string user, string domain)
        {
            this.user = user;
            this.domain = domain;
        }
        static public implicit operator Email(string value)
        {
            var parts = value.Split('@');
            if (parts.Length != 2)
                return null;
            return new Email(parts[0], parts[1]);
        }
        static public implicit operator string(Email value)
        {
            return "User = " + value.user + ", Domain = " + value.domain;
        }
    }

I think it would quite useful in providing conversion operations from one type to another. The simplest candidate would when you have multiple addresses and you need them in a certain format (read Type) to send it to a shipping agency.

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