1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
//-----------------------------------------------------------------------
// <copyright file="EmptyList.cs" company="Outercurve Foundation">
// Copyright (c) Outercurve Foundation. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------
namespace DotNetOpenAuth.Messaging {
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
/// <summary>
/// An empty, read-only list.
/// </summary>
/// <typeparam name="T">The type the list claims to include.</typeparam>
[Serializable]
internal class EmptyList<T> : IList<T> {
/// <summary>
/// The singleton instance of the empty list.
/// </summary>
internal static readonly EmptyList<T> Instance = new EmptyList<T>();
/// <summary>
/// Prevents a default instance of the EmptyList class from being created.
/// </summary>
private EmptyList() {
}
/// <summary>
/// Gets the number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </summary>
/// <value></value>
/// <returns>
/// The number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </returns>
public int Count {
get { return 0; }
}
/// <summary>
/// Gets a value indicating whether the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
/// </summary>
/// <value></value>
/// <returns>true if the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only; otherwise, false.
/// </returns>
public bool IsReadOnly {
get { return true; }
}
#region IList<T> Members
/// <summary>
/// Gets or sets the <typeparamref name="T"/> at the specified index.
/// </summary>
/// <param name="index">The index of the element in the list to change.</param>
/// <returns>Nothing. It always throws.</returns>
public T this[int index] {
get {
throw new ArgumentOutOfRangeException("index");
}
set {
throw new ArgumentOutOfRangeException("index");
}
}
/// <summary>
/// Determines the index of a specific item in the <see cref="T:System.Collections.Generic.IList`1"/>.
/// </summary>
/// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.IList`1"/>.</param>
/// <returns>
/// The index of <paramref name="item"/> if found in the list; otherwise, -1.
/// </returns>
public int IndexOf(T item) {
return -1;
}
/// <summary>
/// Inserts an item to the <see cref="T:System.Collections.Generic.IList`1"/> at the specified index.
/// </summary>
/// <param name="index">The zero-based index at which <paramref name="item"/> should be inserted.</param>
/// <param name="item">The object to insert into the <see cref="T:System.Collections.Generic.IList`1"/>.</param>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// <paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.
/// </exception>
/// <exception cref="T:System.NotSupportedException">
/// The <see cref="T:System.Collections.Generic.IList`1"/> is read-only.
/// </exception>
public void Insert(int index, T item) {
throw new NotSupportedException();
}
/// <summary>
/// Removes the <see cref="T:System.Collections.Generic.IList`1"/> item at the specified index.
/// </summary>
/// <param name="index">The zero-based index of the item to remove.</param>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// <paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.
/// </exception>
/// <exception cref="T:System.NotSupportedException">
/// The <see cref="T:System.Collections.Generic.IList`1"/> is read-only.
/// </exception>
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Code Contracts ccrewrite does this.")]
public void RemoveAt(int index) {
throw new ArgumentOutOfRangeException("index");
}
#endregion
#region ICollection<T> Members
/// <summary>
/// Adds an item to the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </summary>
/// <param name="item">The object to add to the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param>
/// <exception cref="T:System.NotSupportedException">
/// The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
/// </exception>
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Code Contracts ccrewrite does this.")]
public void Add(T item) {
throw new NotSupportedException();
}
/// <summary>
/// Removes all items from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </summary>
/// <exception cref="T:System.NotSupportedException">
/// The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
/// </exception>
public void Clear() {
throw new NotSupportedException();
}
/// <summary>
/// Determines whether the <see cref="T:System.Collections.Generic.ICollection`1"/> contains a specific value.
/// </summary>
/// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param>
/// <returns>
/// true if <paramref name="item"/> is found in the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false.
/// </returns>
public bool Contains(T item) {
return false;
}
/// <summary>
/// Copies the elements of the <see cref="T:System.Collections.Generic.ICollection`1"/> to an <see cref="T:System.Array"/>, starting at a particular <see cref="T:System.Array"/> index.
/// </summary>
/// <param name="array">The one-dimensional <see cref="T:System.Array"/> that is the destination of the elements copied from <see cref="T:System.Collections.Generic.ICollection`1"/>. The <see cref="T:System.Array"/> must have zero-based indexing.</param>
/// <param name="arrayIndex">The zero-based index in <paramref name="array"/> at which copying begins.</param>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="array"/> is null.
/// </exception>
/// <exception cref="T:System.ArgumentOutOfRangeException">
/// <paramref name="arrayIndex"/> is less than 0.
/// </exception>
/// <exception cref="T:System.ArgumentException">
/// <paramref name="array"/> is multidimensional.
/// -or-
/// <paramref name="arrayIndex"/> is equal to or greater than the length of <paramref name="array"/>.
/// -or-
/// The number of elements in the source <see cref="T:System.Collections.Generic.ICollection`1"/> is greater than the available space from <paramref name="arrayIndex"/> to the end of the destination <paramref name="array"/>.
/// -or-
/// Type <typeparamref name="T"/> cannot be cast automatically to the type of the destination <paramref name="array"/>.
/// </exception>
public void CopyTo(T[] array, int arrayIndex) {
}
/// <summary>
/// Removes the first occurrence of a specific object from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </summary>
/// <param name="item">The object to remove from the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param>
/// <returns>
/// true if <paramref name="item"/> was successfully removed from the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false. This method also returns false if <paramref name="item"/> is not found in the original <see cref="T:System.Collections.Generic.ICollection`1"/>.
/// </returns>
/// <exception cref="T:System.NotSupportedException">
/// The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
/// </exception>
public bool Remove(T item) {
return false;
}
#endregion
#region IEnumerable<T> Members
/// <summary>
/// Returns an enumerator that iterates through the collection.
/// </summary>
/// <returns>
/// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
/// </returns>
public IEnumerator<T> GetEnumerator() {
return System.Linq.Enumerable.Empty<T>().GetEnumerator();
}
#endregion
#region IEnumerable Members
/// <summary>
/// Returns an enumerator that iterates through a collection.
/// </summary>
/// <returns>
/// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
/// </returns>
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() {
return EmptyEnumerator.Instance;
}
#endregion
}
}
|
