SubTypeText.cs

    [Serializable]
    public struct SubTypeText {
        private object myValue;

        public SubTypeText(DBNull aDBNull) {
            this.myValue = (object) aDBNull;
        }

        public SubTypeText(string newValue) {
            this.myValue = (object) newValue;
        }

        public bool HasValue {
            get { return this.myValue != DBNull.Value; }
        }

        public override string ToString() {
            return this.myValue.ToString();
        }

        public static implicit operator SubTypeText(string newValue) {
            return new SubTypeText(newValue);
        }

        public static implicit operator SubTypeText(DBNull aDBNull) {
            return new SubTypeText(aDBNull);
        }

        public static implicit operator string(SubTypeText aDBType) {
            return aDBType.myValue.ToString();
        }

        public override bool Equals(object obj) {
            if (this.HasValue)
                return this.myValue.ToString() == obj.ToString();
            if (obj != null)
                return obj == DBNull.Value;
            return true;
        }

        public override int GetHashCode() {
            return this.myValue.GetHashCode();
        }

        public static bool operator ==(SubTypeText aDBType, DBNull aDBNull) {
            return aDBType.myValue == aDBNull;
        }

        public static bool operator !=(SubTypeText aDBType, DBNull aDBNull) {
            return aDBType.myValue != aDBNull;
        }
    }