Singleton.cs :  » Content-Management-Systems-CMS » umbraco » presentation » umbracoBase » C# / CSharp Open Source

using System;

/// <changelog>
///   <item who="Esben" when="17. november 2006">Created</item>
/// </changelog>

namespace umbraco{
  /// <summary>
  /// 
  /// Threadsafe Singleton best practice design pattern template
  /// 
  /// Sample:
  /// 
  /// public class Demo
  /// {
  ///    public static Form1 instance1
  ///    {
  ///      get
  ///      {
  ///        return Singleton<Form1>.Instance;
  ///      }
  ///    }
  ///  }
  /// </summary>
  /// <typeparam name="T">Any class that implements default constructor</typeparam>
  public sealed class Singleton<T> where T : new()
  {
    private Singleton()
    {
    }

    public static T Instance
    {
      get { return Nested.instance; }
    }

    private class Nested
    {
      // Explicit static constructor to tell C# compiler
      // not to mark type as beforefieldinit
      static Nested()
      {
      }

      internal static readonly T instance = new T();
    }
  }
}