# strings/string_digraph.hpp

    #ifndef STLPLUS_STRING_DIGRAPH
    #define STLPLUS_STRING_DIGRAPH
    ////////////////////////////////////////////////////////////////////////////////

    //   Author:    Andy Rushton
    //   Copyright: (c) Southampton University 1999-2004
    //              (c) Andy Rushton           2004 onwards
    //   License:   BSD License, see ../docs/license.html

    //   Generate a string representation of a digraph

    ////////////////////////////////////////////////////////////////////////////////
    #include "strings_fixes.hpp"
    #include "digraph.hpp"
    #include <string>

    ////////////////////////////////////////////////////////////////////////////////

    namespace stlplus
    {

      template<typename NT, typename AT, typename NS, typename AS>
      std::string digraph_to_string(const digraph<NT,AT>& values,
                                    NS node_to_string_fn,
                                    AS arc_to_string_fn,
                                    const std::string& separator = ",");

    } // end namespace stlplus

    #include "string_digraph.tpp"
    #endif