protobuf/csharp/ProtocolBuffers/Collections/Lists.cs
2008-08-14 20:33:34 +01:00

38 lines
971 B
C#

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
namespace Google.ProtocolBuffers.Collections {
public static class Lists {
public static IList<T> AsReadOnly<T>(IList<T> list) {
return Lists<T>.AsReadOnly(list);
}
}
/// <summary>
/// Utilities class for dealing with lists.
/// </summary>
public static class Lists<T> {
static readonly ReadOnlyCollection<T> empty = new ReadOnlyCollection<T>(new T[0]);
/// <summary>
/// Returns an immutable empty list.
/// </summary>
public static ReadOnlyCollection<T> Empty {
get { return empty; }
}
/// <summary>
/// Returns either the original reference if it's already read-only,
/// or a new ReadOnlyCollection wrapping the original list.
/// </summary>
public static IList<T> AsReadOnly(IList<T> list) {
return list.IsReadOnly ? list : new ReadOnlyCollection<T>(list);
}
}
}