Method apply_predicate

external/pugixml/pugixml.cpp:6950–6974

		}

		void apply_predicate(xpath_node_set_raw& ns, size_t first, xpath_ast_node* expr, const xpath_stack& stack)
		{
			assert(ns.size() >= first);

			size_t i = 1;
			size_t size = ns.size() - first;
				
			xpath_node* last = ns.begin() + first;
				
			// remove_if... or well, sort of
			for (xpath_node* it = last; it != ns.end(); ++it, ++i)
			{
				xpath_context c(*it, i, size);
			
				if (expr->rettype() == xpath_type_number)
				{
					if (expr->eval_number(c, stack) == i)
						*last++ = *it;
				}
				else if (expr->eval_boolean(c, stack))
					*last++ = *it;
			}
			
			ns.truncate(last);
		}

		void apply_predicates(xpath_node_set_raw& ns, size_t first, const xpath_stack& stack)
		{