TEST_F(XPathAcceptanceTest, variables)
{
    XPath xpath = compile("$variable");

    xpath.bind_variable("variable", 5.2);
    ASSERT_DOUBLE_EQ(5.2, xpath.number());
}
TEST_F(XPathAcceptanceTest, location_paths_apply_to_variables)
{
    Element *parent = doc.new_element("parent");
    Element *child = add_child(parent, "child");

    XPath xpath = compile("$variable/child");

    Nodeset variable_value;
    variable_value.add(parent);
    xpath.bind_variable("variable", variable_value);

    ASSERT_THAT(xpath.nodeset(), ElementsAre(child));
}