System.Xml.Xsl.Runtime.XsltLibrary.CheckXsltValue C# (CSharp) Method

        internal static void CheckXsltValue(XPathItem item)
        {
            CheckXsltValue(new XmlQueryItemSequence(item));
        }

        public static double ToDouble(XPathItem item)
        {
            XsltLibrary.CheckXsltValue(item);

            if (item.IsNode)
            {
                return(XPathConvert.StringToDouble(item.Value));
            }

            Type itemType = item.ValueType;

            if (itemType == StringType)
            {
                return(XPathConvert.StringToDouble(item.Value));
            }
            else if (itemType == DoubleType)
            {
                return(item.ValueAsDouble);
            }
            else
            {
                Debug.Assert(itemType == BooleanType, $"Unexpected type of atomic sequence {itemType}");
                return(item.ValueAsBoolean ? 1d : 0d);
            }
        }