rapidjson/zh-cn/classrapidjson_1_1_encoding.html

concept Encoding {

    typename Ch;    //! Type of character. A "character" is actually a code unit in unicode's definition.


    enum { supportUnicode = 1 }; // or 0 if not supporting unicode


    //! \brief Encode a Unicode codepoint to an output stream.

    //! \param os Output stream.

    //! \param codepoint An unicode codepoint, ranging from 0x0 to 0x10FFFF inclusively.

    template<typename OutputStream>

    static void Encode(OutputStream& os, unsigned codepoint);


    //! \brief Decode a Unicode codepoint from an input stream.

    //! \param is Input stream.

    //! \param codepoint Output of the unicode codepoint.

    //! \return true if a valid codepoint can be decoded from the stream.

    template <typename InputStream>

    static bool Decode(InputStream& is, unsigned* codepoint);


    //! \brief Validate one Unicode codepoint from an encoded stream.

    //! \param is Input stream to obtain codepoint.

    //! \param os Output for copying one codepoint.

    //! \return true if it is valid.

    //! \note This function just validating and copying the codepoint without actually decode it.

    template <typename InputStream, typename OutputStream>

    static bool Validate(InputStream& is, OutputStream& os);


    // The following functions are deal with byte streams.


    //! Take a character from input byte stream, skip BOM if exist.

    template <typename InputByteStream>

    static CharType TakeBOM(InputByteStream& is);


    //! Take a character from input byte stream.

    template <typename InputByteStream>

    static Ch Take(InputByteStream& is);


    //! Put BOM to output byte stream.

    template <typename OutputByteStream>

    static void PutBOM(OutputByteStream& os);


    //! Put a character to output byte stream.

    template <typename OutputByteStream>

    static void Put(OutputByteStream& os, Ch c);

};