Class file_input_adapter

lesson6-Segmentation/json.hpp:4754–4778

! Input adapter for stdio file access. This adapter read only 1 byte and do not use any buffer. This adapter is a very low level adapter. */

 buffer. This adapter is a very low level adapter.
*/
class file_input_adapter
{
  public:
    using char_type = char;

    JSON_HEDLEY_NON_NULL(2)
    explicit file_input_adapter(std::FILE* f) noexcept
        : m_file(f)
    {}

    // make class move-only
    file_input_adapter(const file_input_adapter&) = delete;
    file_input_adapter(file_input_adapter&&) = default;
    file_input_adapter& operator=(const file_input_adapter&) = delete;
    file_input_adapter& operator=(file_input_adapter&&) = delete;

    std::char_traits<char>::int_type get_character() noexcept
    {
        return std::fgetc(m_file);
    }

  private:
    /// the file pointer to read from
    std::FILE* m_file;
};


/*!