With this example, we see how to deal with tag.
#include <iostream>
#include <ximol/ximol.hpp>
using namespace std;
using namespace ximol;
int main()
{
double d1=3.01,d2=4.1;
xstringstream xss;
xss << xml::stag("Example");
xss << xml::etag();
return 0;
};