RECS0015 has semantic consequences

[jnyrup]

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Take this snippet of code.

public static bool SequenceEqual<TSource>(
    this IEnumerable<TSource> first,
    IEnumerable<TSource> second,
    IEqualityComparer<TSource> comparer = null)
{
    if (first is ICollection<TSource> firstCollection
        && second is ICollection<TSource> secondCollection
        && firstCollection.Count != secondCollection.Count)
    {
        return false;
    }

    return Enumerable.SequenceEqual(first, second, comparer);
}

RECS0015 suggests that

Enumerable.SequenceEqual(first, second, comparer)

should be replaced with

first.SequenceEqual(second, comparer)

But that is semantically different as the replaced method call now calls itself instead of System.Linq.Enumerable.SequenceEqual.