String data types for ASN1 library.

The character string data types use predicate objects to define what is allowed to beassigned to the string type. The ASN1 speicifications list a variety of string types, (e.g. NUMERIC, IA5, PRINTABLE) that only allow for a limited character set.

The basic predicate concept is as follows:

struct predicate
{
  bool operator()(const char c);
};

namespace boost {
  namespace asn1 {
    struct pred_numeric;
    struct pred_printable;
    struct pred_t61;
    struct pred_videotext;
    struct pred_ia5;
    struct pred_graphic;
    struct pred_iso646;
    struct pred_general;
    struct pred_utf8;
    struct pred_octet;

    template<typename charT, primitives_t P, typename predT> class string_t;

    typedef string_t< char, _numericstring, pred_numeric > numericstring_t;  // String type for the NUMERIC STRING primitive String type for the PRINTABLE STRING primitive. 
    typedef string_t< char, _printablestring, pred_printable > printablestring_t;  // String type for the T61 STRING primitive. 
    typedef string_t< char, _t61string, pred_t61 > t61string_t;  // String type for the VIDEOTEXT STRING primitive. 
    typedef string_t< char, _videotextstring, pred_videotext > videotextstring_t;  // String type for the IA5 STRING primitive. 
    typedef string_t< char, _ia5string, pred_ia5 > ia5string_t;  // String type for the GRAPHIC STRING primitive. 
    typedef string_t< char, _graphicstring, pred_graphic > graphicstring_t;  // String type for the ISO646 STRING primitive. 
    typedef string_t< char, _iso646string, pred_iso646 > iso646string_t;  // String type for the GENERAL STRING primitive. 
    typedef string_t< char, _generalstring, pred_general > generalstring_t;  // String type for the UTF8 STRING primitive. 
    typedef string_t< wchar_t, _utf8string, pred_utf8 > utf8string_t;  // String type for the OCTET STRING primitive. 
    typedef string_t< char, _octetstring, pred_octet > octetstring_t;
    template<typename charT, primitives_t P, typename predT> 
      ostream & operator<<(ostream &, const string_t< charT, P, predT > &);
  }
}namespace algorithm {
}