XPathUtility.cs

using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;

namespace System.Xml.XPath
{
	public static class XPathUtility
	{
		public static IEnumerable<T> XPathSelectElements<T>(this XNode xNode, string xpath)
			where T : XObject
		{
			return ((IEnumerable<object>)xNode.XPathEvaluate(xpath)).Cast<T>();
		}

		public static string GetValue(this XObject xObject)
		{
			return
				xObject is XAttribute
					? ((XAttribute)xObject).Value :
				xObject is XText
					? ((XText)xObject).Value
					: ((XElement)xObject).Value;
		}
	}
}