Created
August 28, 2012 10:42
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ILambdaEqualityComparer<T>
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| /// <summary> | |
| /// Checks object of type <typeparamref name="T"/> for equality using provided delegates. | |
| /// </summary> | |
| /// <remarks>Use this class to avoid creating nested, narrow-scoped implementation of <see cref="IEqualityComparer{T}"/></remarks> | |
| /// <typeparam name="T">Type that comparer will able to compare.</typeparam> | |
| public class LambdaEqualityComparer<T> : IEqualityComparer<T> | |
| { | |
| private readonly Func<T, T, bool> _equalityCheck; | |
| private readonly Func<T, int> _hashCodeProvider; | |
| /// <summary> | |
| /// Initializes a new instance of the <see cref="LambdaEqualityComparer{T}"/> class using | |
| /// given <paramref name="equalityCheck"/> and <paramref name="hashCodeProvider"/>. | |
| /// </summary> | |
| /// <param name="equalityCheck"></param> /// <param name="hashCodeProvider"></param> | |
| public LambdaEqualityComparer(Func<T, T, bool> equalityCheck, Func<T, int> hashCodeProvider) | |
| { | |
| if (equalityCheck == null) | |
| { | |
| throw new ArgumentNullException("equalityCheck"); | |
| } | |
| if (hashCodeProvider == null) | |
| { | |
| throw new ArgumentNullException("hashCodeProvider"); | |
| } | |
| _equalityCheck = equalityCheck; | |
| _hashCodeProvider = hashCodeProvider; | |
| } | |
| /// <summary> | |
| /// Determines whether the specified objects are equal. | |
| /// </summary> | |
| /// <returns> | |
| /// true if the specified objects are equal; otherwise, false. | |
| /// </returns> | |
| /// <param name="x">The first object of type <typeparamref name="T"/> to compare.</param> | |
| /// <param name="y">The second object of type <typeparamref name="T"/> to compare.</param> | |
| public bool Equals(T x, T y) | |
| { | |
| return _equalityCheck(x, y); | |
| } | |
| /// <summary> | |
| /// Returns a hash code for the specified object. | |
| /// </summary> | |
| /// <returns> | |
| /// A hash code for the specified object. | |
| /// </returns> | |
| /// <param name="obj">The <see cref="T:System.Object"/> for which a hash code is to be returned.</param> | |
| /// <exception cref="T:System.ArgumentNullException"> | |
| /// The type of <paramref name="obj"/> is a reference type and <paramref name="obj"/> is null.</exception> | |
| public int GetHashCode(T obj) | |
| { | |
| if (!typeof(T).IsValueType && obj == null) | |
| { | |
| throw new ArgumentNullException("obj"); | |
| } | |
| return _hashCodeProvider(obj); | |
| } | |
| } |
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