+inline bool contains(std::string const & a, std::string const & b)
+{
+ return a.find(b) != std::string::npos;
+}
+
+inline bool contains(docstring const & a, docstring const & b)
+{
+ return a.find(b) != docstring::npos;
+}
+
+inline bool contains(std::string const & a, char b)