doxygen/a26955.html

concept Encoding {
    typename Ch;
    enum { supportUnicode = 1 }; // or 0 if not supporting unicode
    template<typename OutputStream>
    static void Encode(OutputStream& os, unsigned codepoint);
    template <typename InputStream>
    static bool Decode(InputStream& is, unsigned* codepoint);
    template <typename InputStream, typename OutputStream>
    static bool Validate(InputStream& is, OutputStream& os);
    // The following functions are deal with byte streams.
    template <typename InputByteStream>
    static CharType TakeBOM(InputByteStream& is);
    template <typename InputByteStream>
    static Ch Take(InputByteStream& is);
    template <typename OutputByteStream>
    static void PutBOM(OutputByteStream& os);
    template <typename OutputByteStream>
    static void Put(OutputByteStream& os, Ch c);
};