/// <summary>
/// Returns a hash code for the specified object.
/// </summary>
/// <param name="obj">The object for which to return a hash code. This object may be <c>null</c>.</param>
/// <returns>A hash code for the specified object.</returns>
protected override int DoGetHashCode(T obj)
{
unchecked
{
var ret = (int)2166136261;
ret += ComparerHelpers.GetHashCodeFromComparer(_source, obj);
ret *= 16777619;
ret += ComparerHelpers.GetHashCodeFromComparer(_secondSource, obj);
ret *= 16777619;
return(ret);
}
}
/// <summary>
/// Returns a hash code for the specified object.
/// </summary>
/// <param name="obj">The object for which to return a hash code.</param>
/// <returns>A hash code for the specified object.</returns>
protected override int DoGetHashCode(IEnumerable <T> obj)
{
unchecked
{
var ret = (int)2166136261;
foreach (var item in obj)
{
ret += ComparerHelpers.GetHashCodeFromComparer(_source, item);
ret *= 16777619;
}
return(ret);
}
}
/// <summary>
/// Returns a hash code for the specified object.
/// </summary>
/// <param name="obj">The object for which to return a hash code. This object may be <c>null</c>.</param>
/// <returns>A hash code for the specified object.</returns>
protected override int DoGetHashCode(T obj)
{
return(ComparerHelpers.GetHashCodeFromComparer(_source, obj));
}
/// <summary>
/// Initializes a new instance of the <see cref="CompoundComparer<T>"/> class.
/// </summary>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="secondSource">The second comparer. If this is <c>null</c>, the default comparer is used.</param>
public CompoundComparer(IComparer <T>?source, IComparer <T>?secondSource)
: base(source, null, true)
{
_secondSource = ComparerHelpers.NormalizeDefault(secondSource);
_secondSourceGetHashCode = ComparerHelpers.ComparerGetHashCode(_secondSource);
}
/// <summary>
/// Initializes a new instance of the <see cref="SourceComparerBase<T, TSource>"/> class.
/// </summary>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="getHashCode">The <c>GetHashCode</c> implementation to use. If this is <c>null</c>, this type will attempt to find <c>GetHashCode</c> on <paramref name="source"/>; if none is found, throws an exception.</param>
/// <param name="specialNullHandling">A value indicating whether <c>null</c> values are passed to <see cref="EqualityComparerBase{T}.DoGetHashCode"/> and <see cref="ComparerBase{T}.DoCompare"/>. If <c>false</c>, then <c>null</c> values are considered less than any non-<c>null</c> values and are not passed to <see cref="EqualityComparerBase{T}.DoGetHashCode"/> nor <see cref="ComparerBase{T}.DoCompare"/>. This value is ignored if <typeparamref name="T"/> is a non-nullable type.</param>
protected SourceComparerBase(IComparer <TSource>?source, Func <TSource, int>?getHashCode, bool specialNullHandling)
: base(specialNullHandling)
{
Source = ComparerHelpers.NormalizeDefault(source);
SourceGetHashCode = getHashCode ?? ComparerHelpers.ComparerGetHashCode(Source);
}
/// <summary>
/// Initializes a new instance of the <see cref="SourceComparerBase<T, TSource>"/> class.
/// </summary>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="specialNullHandling">A value indicating whether <c>null</c> values are passed to <see cref="EqualityComparerBase{T}.DoGetHashCode"/> and <see cref="ComparerBase{T}.DoCompare"/>. If <c>false</c>, then <c>null</c> values are considered less than any non-<c>null</c> values and are not passed to <see cref="EqualityComparerBase{T}.DoGetHashCode"/> nor <see cref="ComparerBase{T}.DoCompare"/>.</param>
protected SourceComparerBase(IComparer <TSource> source, bool specialNullHandling)
: base(specialNullHandling)
{
_source = ComparerHelpers.NormalizeDefault(source);
}
/// <summary>
/// Initializes a new instance of the <see cref="CompoundComparer<T>"/> class.
/// </summary>
/// <param name="source">The source comparer. If this is <c>null</c>, the default comparer is used.</param>
/// <param name="secondSource">The second comparer. If this is <c>null</c>, the default comparer is used.</param>
public CompoundComparer(IComparer <T> source, IComparer <T> secondSource)
: base(source, true)
{
_secondSource = ComparerHelpers.NormalizeDefault(secondSource);
}
