TupleComparer that takes a IEqualityComparer (e.g. StringComparer.OrdinalIgnoreCase)

TupleComparer.cs

/// <summary>
/// Compares tuples of 2 items of the same type, using the specified comparer.
/// </summary>
class TupleComparer<T> : IEqualityComparer<(T, T)>
{
    IEqualityComparer<T> _comparer;
    public TupleComparer(IEqualityComparer<T> comparer) => _comparer = comparer;
    public bool Equals((T, T) x, (T, T) y) => _comparer.Equals(x.Item1, y.Item1) && _comparer.Equals(x.Item2, y.Item2);
    public int GetHashCode((T, T) obj) => HashCode.Combine(_comparer.GetHashCode(obj.Item1), _comparer.GetHashCode(obj.Item2));
}