Function element_path_from_xpath

native/thirdpart/tinyxml2/tixml2ex.h:163–209

		template <typename XE> inline element_path_t<XE> element_path_from_xpath (XE * root, const std::string & xpath)
		{
			if (!root)
				throw XmlException ("null element"s);

			element_path_t<XE> ep;

			// split the path
			size_t start = 0;
			size_t pos;
			// set element at head of selection branch
			//	if path starts with '/' then it is relative to document, otherwise relative to element passed in
			// first element in selection branch is the root and only children of the root are considered
			// for document-based paths, this works because there can only be one document element
			if (!xpath.empty() && xpath[0] == '/')
			{
				// document is not an element so needs special handling
				// advance to the actual document element
				// note that document element must still appear in path, so we have to step over it
				++start;
				if ((pos = xpath .find ('/', start)) != std::string::npos)
				{
					auto filter = ElementProperties (xpath .substr (start, pos - start));
					auto element = root -> GetDocument() -> RootElement();
					if (element && !filter .Name() .empty())
					{
						if (filter .Name() != std::string (element -> Name()))
							throw XmlException ("document element name mismatch"s);
					}
					ep .emplace_back (std::make_pair (filter, element));
					start = pos + 1;
				}
			}
			else
				ep .emplace_back (std::make_pair (ElementProperties (root -> Name()), root));

			// continue with other elements along path
			while ((pos = xpath .find ('/', start)) != std::string::npos)
			{
				ep .emplace_back (std::make_pair (ElementProperties (xpath .substr (start, pos - start)), nullptr));
				start = pos + 1;
			}
			// and the final element
			ep .emplace_back (std::make_pair (ElementProperties (xpath .substr (start, pos - start)), nullptr));

			return ep;
		}


		template <typename XE> inline element_path_t<XE> element_path_from_element (XE * e)