// Example of custom attributes (see Liberty, "Programming C# 3.0", Chapter 20)
// Defines a BugFix attribute, capturing data on code changes

// Example 20-1. Working with custom attributes
using System;
namespace CustomAttributes
{
    // create custom attribute to be assigned to class members
    [AttributeUsage(AttributeTargets.Class |
                    AttributeTargets.Constructor |
                    AttributeTargets.Field |
                    AttributeTargets.Method |
                    AttributeTargets.Property,
                    AllowMultiple = true)]
    public class BugFixAttribute : System.Attribute
    {
        // attribute constructor for positional parameters
        public BugFixAttribute
        (
            int bugID,
            string programmer,
            string date
        )
        {
            this.BugID = bugID;
            this.Programmer = programmer;
            this.Date = date;
        }
        // accessors
        public int BugID { get; private set; }
        public string Date { get; private set; }
        public string Programmer { get; private set; }
        // property for named parameter
        public string Comment { get; set; }
    }
    // ********* assign the attributes to the class ********
    [BugFixAttribute(121, "Jesse Liberty", "01/03/08")]
    [BugFixAttribute(107, "Jesse Liberty", "01/04/08",
                        Comment = "Fixed off by one errors")]
    public class MyMath
    {
        public double DoFunc1(double param1)
        {
            return param1 + DoFunc2(param1);
        }
        public double DoFunc2(double param1)
        {
            return param1 / 3;
        }
    }
    public class Tester
    {
        static void Main(string[] args)
        {
            MyMath mm = new MyMath( );
            Console.WriteLine("Calling DoFunc(7). Result: {0}",
            mm.DoFunc1(7));
        }
    }
}

/*
Output:
Calling DoFunc(7). Result: 9.3333333333333333
*/