Add missing functions to VorbisComment class.

[flac.git] / include / FLAC++ / metadata.h

/* libFLAC++ - Free Lossless Audio Codec library
 * Copyright (C) 2002,2003,2004,2005,2006,2007,2008,2009  Josh Coalson
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FLACPP__METADATA_H
#define FLACPP__METADATA_H

#include "export.h"

#include "FLAC/metadata.h"

// ===============================================================
//
//  Full documentation for the metadata interface can be found
//  in the C layer in include/FLAC/metadata.h
//
// ===============================================================

/** \file include/FLAC++/metadata.h
 *
 *  \brief
 *  This module provides classes for creating and manipulating FLAC
 *  metadata blocks in memory, and three progressively more powerful
 *  interfaces for traversing and editing metadata in FLAC files.
 *
 *  See the detailed documentation for each interface in the
 *  \link flacpp_metadata metadata \endlink module.
 */

/** \defgroup flacpp_metadata FLAC++/metadata.h: metadata interfaces
 *  \ingroup flacpp
 *
 *  \brief
 *  This module provides classes for creating and manipulating FLAC
 *  metadata blocks in memory, and three progressively more powerful
 *  interfaces for traversing and editing metadata in FLAC files.
 *
 *  The behavior closely mimics the C layer interface; be sure to read
 *  the detailed description of the
 *  \link flac_metadata C metadata module \endlink.  Note that like the
 *  C layer, currently only the Chain interface (level 2) supports Ogg
 *  FLAC files, and it is read-only i.e. no writing back changed
 *  metadata to file.
 */


namespace FLAC {
        namespace Metadata {

                // ============================================================
                //
                //  Metadata objects
                //
                // ============================================================

                /** \defgroup flacpp_metadata_object FLAC++/metadata.h: metadata object classes
                 *  \ingroup flacpp_metadata
                 *
                 * This module contains classes representing FLAC metadata
                 * blocks in memory.
                 *
                 * The behavior closely mimics the C layer interface; be
                 * sure to read the detailed description of the
                 * \link flac_metadata_object C metadata object module \endlink.
                 *
                 * Any time a metadata object is constructed or assigned, you
                 * should check is_valid() to make sure the underlying
                 * ::FLAC__StreamMetadata object was able to be created.
                 *
                 * \warning
                 * When the get_*() methods of any metadata object method
                 * return you a const pointer, DO NOT disobey and write into it.
                 * Always use the set_*() methods.
                 *
                 * \{
                 */

                /** Base class for all metadata block types.
                 *  See the \link flacpp_metadata_object overview \endlink for more.
                 */
                class FLACPP_API Prototype {
                protected:
                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        Prototype(const Prototype &);
                        Prototype(const ::FLAC__StreamMetadata &);
                        Prototype(const ::FLAC__StreamMetadata *);
                        //@}

                        /** Constructs an object with copy control.  When \a copy
                         *  is \c true, behaves identically to
                         *  FLAC::Metadata::Prototype::Prototype(const ::FLAC__StreamMetadata *object).
                         *  When \a copy is \c false, the instance takes ownership of
                         *  the pointer and the ::FLAC__StreamMetadata object will
                         *  be freed by the destructor.
                         *
                         *  \assert
                         *    \code object != NULL \endcode
                         */
                        Prototype(::FLAC__StreamMetadata *object, bool copy);

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        Prototype &operator=(const Prototype &);
                        Prototype &operator=(const ::FLAC__StreamMetadata &);
                        Prototype &operator=(const ::FLAC__StreamMetadata *);
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        Prototype &assign_object(::FLAC__StreamMetadata *object, bool copy);

                        /** Deletes the underlying ::FLAC__StreamMetadata object.
                         */
                        virtual void clear();

                        ::FLAC__StreamMetadata *object_;
                public:
                        /** Deletes the underlying ::FLAC__StreamMetadata object.
                         */
                        virtual ~Prototype();

                        //@{
                        /** Check for equality, performing a deep compare by following pointers.
                         */
                        inline bool operator==(const Prototype &) const;
                        inline bool operator==(const ::FLAC__StreamMetadata &) const;
                        inline bool operator==(const ::FLAC__StreamMetadata *) const;
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const Prototype &) const;
                        inline bool operator!=(const ::FLAC__StreamMetadata &) const;
                        inline bool operator!=(const ::FLAC__StreamMetadata *) const;
                        //@}

                        friend class SimpleIterator;
                        friend class Iterator;

                        /** Returns \c true if the object was correctly constructed
                         *  (i.e. the underlying ::FLAC__StreamMetadata object was
                         *  properly allocated), else \c false.
                         */
                        inline bool is_valid() const;

                        /** Returns \c true if this block is the last block in a
                         *  stream, else \c false.
                         *
                         * \assert
                         *   \code is_valid() \endcode
                         */
                        bool get_is_last() const;

                        /** Returns the type of the block.
                         *
                         * \assert
                         *   \code is_valid() \endcode
                         */
                        ::FLAC__MetadataType get_type() const;

                        /** Returns the stream length of the metadata block.
                         *
                         * \note
                         *   The length does not include the metadata block header,
                         *   per spec.
                         *
                         * \assert
                         *   \code is_valid() \endcode
                         */
                        unsigned get_length() const;

                        /** Sets the "is_last" flag for the block.  When using the iterators
                         *  it is not necessary to set this flag; they will do it for you.
                         *
                         * \assert
                         *   \code is_valid() \endcode
                         */
                        void set_is_last(bool);

                        /** Returns a pointer to the underlying ::FLAC__StreamMetadata
                         *  object.  This can be useful for plugging any holes between
                         *  the C++ and C interfaces.
                         *
                         * \assert
                         *   \code is_valid() \endcode
                         */
                        inline operator const ::FLAC__StreamMetadata *() const;
                private:
                        /** Private and undefined so you can't use it. */
                        Prototype();

                        // These are used only by Iterator
                        bool is_reference_;
                        inline void set_reference(bool x) { is_reference_ = x; }
                };

#ifdef _MSC_VER
// warning C4800: 'int' : forcing to bool 'true' or 'false' (performance warning)
#pragma warning ( disable : 4800 )
#endif

                inline bool Prototype::operator==(const Prototype &object) const
                { return (bool)::FLAC__metadata_object_is_equal(object_, object.object_); }

                inline bool Prototype::operator==(const ::FLAC__StreamMetadata &object) const
                { return (bool)::FLAC__metadata_object_is_equal(object_, &object); }

                inline bool Prototype::operator==(const ::FLAC__StreamMetadata *object) const
                { return (bool)::FLAC__metadata_object_is_equal(object_, object); }

#ifdef _MSC_VER
// @@@ how to re-enable?  the following doesn't work
// #pragma warning ( enable : 4800 )
#endif

                inline bool Prototype::operator!=(const Prototype &object) const
                { return !operator==(object); }

                inline bool Prototype::operator!=(const ::FLAC__StreamMetadata &object) const
                { return !operator==(object); }

                inline bool Prototype::operator!=(const ::FLAC__StreamMetadata *object) const
                { return !operator==(object); }

                inline bool Prototype::is_valid() const
                { return 0 != object_; }

                inline Prototype::operator const ::FLAC__StreamMetadata *() const
                { return object_; }

                /** Create a deep copy of an object and return it. */
                FLACPP_API Prototype *clone(const Prototype *);


                /** STREAMINFO metadata block.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 *  and the <A HREF="../format.html#metadata_block_streaminfo">format specification</A>.
                 */
                class FLACPP_API StreamInfo : public Prototype {
                public:
                        StreamInfo();

                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline StreamInfo(const StreamInfo &object): Prototype(object) { }
                        inline StreamInfo(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline StreamInfo(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline StreamInfo(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~StreamInfo();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline StreamInfo &operator=(const StreamInfo &object) { Prototype::operator=(object); return *this; }
                        inline StreamInfo &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline StreamInfo &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline StreamInfo &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const StreamInfo &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const StreamInfo &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        //@{
                        /** See <A HREF="../format.html#metadata_block_streaminfo">format specification</A>. */
                        unsigned get_min_blocksize() const;
                        unsigned get_max_blocksize() const;
                        unsigned get_min_framesize() const;
                        unsigned get_max_framesize() const;
                        unsigned get_sample_rate() const;
                        unsigned get_channels() const;
                        unsigned get_bits_per_sample() const;
                        FLAC__uint64 get_total_samples() const;
                        const FLAC__byte *get_md5sum() const;

                        void set_min_blocksize(unsigned value);
                        void set_max_blocksize(unsigned value);
                        void set_min_framesize(unsigned value);
                        void set_max_framesize(unsigned value);
                        void set_sample_rate(unsigned value);
                        void set_channels(unsigned value);
                        void set_bits_per_sample(unsigned value);
                        void set_total_samples(FLAC__uint64 value);
                        void set_md5sum(const FLAC__byte value[16]);
                        //@}
                };

                /** PADDING metadata block.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 *  and the <A HREF="../format.html#metadata_block_padding">format specification</A>.
                 */
                class FLACPP_API Padding : public Prototype {
                public:
                        Padding();

                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline Padding(const Padding &object): Prototype(object) { }
                        inline Padding(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline Padding(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Padding(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~Padding();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline Padding &operator=(const Padding &object) { Prototype::operator=(object); return *this; }
                        inline Padding &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline Padding &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Padding &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const Padding &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const Padding &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        void set_length(unsigned length);
                };

                /** APPLICATION metadata block.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 *  and the <A HREF="../format.html#metadata_block_application">format specification</A>.
                 */
                class FLACPP_API Application : public Prototype {
                public:
                        Application();
                        //
                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline Application(const Application &object): Prototype(object) { }
                        inline Application(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline Application(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Application(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~Application();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline Application &operator=(const Application &object) { Prototype::operator=(object); return *this; }
                        inline Application &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline Application &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Application &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const Application &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const Application &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        const FLAC__byte *get_id() const;
                        const FLAC__byte *get_data() const;

                        void set_id(const FLAC__byte value[4]);
                        //! This form always copies \a data
                        bool set_data(const FLAC__byte *data, unsigned length);
                        bool set_data(FLAC__byte *data, unsigned length, bool copy);
                };

                /** SEEKTABLE metadata block.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 *  and the <A HREF="../format.html#metadata_block_seektable">format specification</A>.
                 */
                class FLACPP_API SeekTable : public Prototype {
                public:
                        SeekTable();

                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline SeekTable(const SeekTable &object): Prototype(object) { }
                        inline SeekTable(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline SeekTable(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline SeekTable(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~SeekTable();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline SeekTable &operator=(const SeekTable &object) { Prototype::operator=(object); return *this; }
                        inline SeekTable &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline SeekTable &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline SeekTable &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const SeekTable &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const SeekTable &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        unsigned get_num_points() const;
                        ::FLAC__StreamMetadata_SeekPoint get_point(unsigned index) const;

                        //! See FLAC__metadata_object_seektable_resize_points()
                        bool resize_points(unsigned new_num_points);

                        //! See FLAC__metadata_object_seektable_set_point()
                        void set_point(unsigned index, const ::FLAC__StreamMetadata_SeekPoint &point);

                        //! See FLAC__metadata_object_seektable_insert_point()
                        bool insert_point(unsigned index, const ::FLAC__StreamMetadata_SeekPoint &point);

                        //! See FLAC__metadata_object_seektable_delete_point()
                        bool delete_point(unsigned index);

                        //! See FLAC__metadata_object_seektable_is_legal()
                        bool is_legal() const;

                        //! See FLAC__metadata_object_seektable_template_append_placeholders()
                        bool template_append_placeholders(unsigned num);

                        //! See FLAC__metadata_object_seektable_template_append_point()
                        bool template_append_point(FLAC__uint64 sample_number);

                        //! See FLAC__metadata_object_seektable_template_append_points()
                        bool template_append_points(FLAC__uint64 sample_numbers[], unsigned num);

                        //! See FLAC__metadata_object_seektable_template_append_spaced_points()
                        bool template_append_spaced_points(unsigned num, FLAC__uint64 total_samples);

                        //! See FLAC__metadata_object_seektable_template_append_spaced_points_by_samples()
                        bool template_append_spaced_points_by_samples(unsigned samples, FLAC__uint64 total_samples);

                        //! See FLAC__metadata_object_seektable_template_sort()
                        bool template_sort(bool compact);
                };

                /** VORBIS_COMMENT metadata block.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 *  and the <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>.
                 */
                class FLACPP_API VorbisComment : public Prototype {
                public:
                        /** Convenience class for encapsulating Vorbis comment
                         *  entries.  An entry is a vendor string or a comment
                         *  field.  In the case of a vendor string, the field
                         *  name is undefined; only the field value is relevant.
                         *
                         *  A \a field as used in the methods refers to an
                         *  entire 'NAME=VALUE' string; for convenience the
                         *  string is NUL-terminated.  A length field is
                         *  required in the unlikely event that the value
                         *  contains contain embedded NULs.
                         *
                         *  A \a field_name is what is on the left side of the
                         *  first '=' in the \a field.  By definition it is ASCII
                         *  and so is NUL-terminated and does not require a
                         *  length to describe it.  \a field_name is undefined
                         *  for a vendor string entry.
                         *
                         *  A \a field_value is what is on the right side of the
                         *  first '=' in the \a field.  By definition, this may
                         *  contain embedded NULs and so a \a field_value_length
                         *  is required to describe it.  However in practice,
                         *  embedded NULs are not known to be used, so it is
                         *  generally safe to treat field values as NUL-
                         *  terminated UTF-8 strings.
                         *
                         *  Always check is_valid() after the constructor or operator=
                         *  to make sure memory was properly allocated and that the
                         *  Entry conforms to the Vorbis comment specification.
                         */
                        class FLACPP_API Entry {
                        public:
                                Entry();

                                Entry(const char *field, unsigned field_length);
                                Entry(const char *field); // assumes \a field is NUL-terminated

                                Entry(const char *field_name, const char *field_value, unsigned field_value_length);
                                Entry(const char *field_name, const char *field_value); // assumes \a field_value is NUL-terminated

                                Entry(const Entry &entry);

                                Entry &operator=(const Entry &entry);

                                virtual ~Entry();

                                virtual bool is_valid() const; ///< Returns \c true iff object was properly constructed.

                                unsigned get_field_length() const;
                                unsigned get_field_name_length() const;
                                unsigned get_field_value_length() const;

                                ::FLAC__StreamMetadata_VorbisComment_Entry get_entry() const;
                                const char *get_field() const;
                                const char *get_field_name() const;
                                const char *get_field_value() const;

                                bool set_field(const char *field, unsigned field_length);
                                bool set_field(const char *field); // assumes \a field is NUL-terminated
                                bool set_field_name(const char *field_name);
                                bool set_field_value(const char *field_value, unsigned field_value_length);
                                bool set_field_value(const char *field_value); // assumes \a field_value is NUL-terminated
                        protected:
                                bool is_valid_;
                                ::FLAC__StreamMetadata_VorbisComment_Entry entry_;
                                char *field_name_;
                                unsigned field_name_length_;
                                char *field_value_;
                                unsigned field_value_length_;
                        private:
                                void zero();
                                void clear();
                                void clear_entry();
                                void clear_field_name();
                                void clear_field_value();
                                void construct(const char *field, unsigned field_length);
                                void construct(const char *field); // assumes \a field is NUL-terminated
                                void construct(const char *field_name, const char *field_value, unsigned field_value_length);
                                void construct(const char *field_name, const char *field_value); // assumes \a field_value is NUL-terminated
                                void compose_field();
                                void parse_field();
                        };

                        VorbisComment();

                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline VorbisComment(const VorbisComment &object): Prototype(object) { }
                        inline VorbisComment(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline VorbisComment(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline VorbisComment(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~VorbisComment();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline VorbisComment &operator=(const VorbisComment &object) { Prototype::operator=(object); return *this; }
                        inline VorbisComment &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline VorbisComment &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline VorbisComment &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const VorbisComment &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const VorbisComment &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        unsigned get_num_comments() const;
                        const FLAC__byte *get_vendor_string() const; // NUL-terminated UTF-8 string
                        Entry get_comment(unsigned index) const;

                        //! See FLAC__metadata_object_vorbiscomment_set_vendor_string()
                        bool set_vendor_string(const FLAC__byte *string); // NUL-terminated UTF-8 string

                        //! See FLAC__metadata_object_vorbiscomment_resize_comments()
                        bool resize_comments(unsigned new_num_comments);

                        //! See FLAC__metadata_object_vorbiscomment_set_comment()
                        bool set_comment(unsigned index, const Entry &entry);

                        //! See FLAC__metadata_object_vorbiscomment_insert_comment()
                        bool insert_comment(unsigned index, const Entry &entry);

                        //! See FLAC__metadata_object_vorbiscomment_append_comment()
                        bool append_comment(const Entry &entry);

                        //! See FLAC__metadata_object_vorbiscomment_replace_comment()
                        bool replace_comment(const Entry &entry, bool all);

                        //! See FLAC__metadata_object_vorbiscomment_delete_comment()
                        bool delete_comment(unsigned index);

                        //! See FLAC__metadata_object_vorbiscomment_find_entry_from()
                        int find_entry_from(unsigned offset, const char *field_name);

                        //! See FLAC__metadata_object_vorbiscomment_remove_entry_matching()
                        int remove_entry_matching(const char *field_name);

                        //! See FLAC__metadata_object_vorbiscomment_remove_entries_matching()
                        int remove_entries_matching(const char *field_name);
                };

                /** CUESHEET metadata block.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 *  and the <A HREF="../format.html#metadata_block_cuesheet">format specification</A>.
                 */
                class FLACPP_API CueSheet : public Prototype {
                public:
                        /** Convenience class for encapsulating a cue sheet
                         *  track.
                         *
                         *  Always check is_valid() after the constructor or operator=
                         *  to make sure memory was properly allocated.
                         */
                        class FLACPP_API Track {
                        protected:
                                ::FLAC__StreamMetadata_CueSheet_Track *object_;
                        public:
                                Track();
                                Track(const ::FLAC__StreamMetadata_CueSheet_Track *track);
                                Track(const Track &track);
                                Track &operator=(const Track &track);

                                virtual ~Track();

                                virtual bool is_valid() const; ///< Returns \c true iff object was properly constructed.


                                inline FLAC__uint64 get_offset() const { return object_->offset; }
                                inline FLAC__byte get_number() const { return object_->number; }
                                inline const char *get_isrc() const { return object_->isrc; }
                                inline unsigned get_type() const { return object_->type; }
                                inline bool get_pre_emphasis() const { return object_->pre_emphasis; }

                                inline FLAC__byte get_num_indices() const { return object_->num_indices; }
                                ::FLAC__StreamMetadata_CueSheet_Index get_index(unsigned i) const;

                                inline const ::FLAC__StreamMetadata_CueSheet_Track *get_track() const { return object_; }

                                inline void set_offset(FLAC__uint64 value) { object_->offset = value; }
                                inline void set_number(FLAC__byte value) { object_->number = value; }
                                void set_isrc(const char value[12]);
                                void set_type(unsigned value);
                                inline void set_pre_emphasis(bool value) { object_->pre_emphasis = value? 1 : 0; }

                                void set_index(unsigned i, const ::FLAC__StreamMetadata_CueSheet_Index &index);
                                //@@@ It's awkward but to insert/delete index points
                                //@@@ you must use the routines in the CueSheet class.
                        };

                        CueSheet();

                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline CueSheet(const CueSheet &object): Prototype(object) { }
                        inline CueSheet(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline CueSheet(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline CueSheet(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~CueSheet();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline CueSheet &operator=(const CueSheet &object) { Prototype::operator=(object); return *this; }
                        inline CueSheet &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline CueSheet &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline CueSheet &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const CueSheet &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const CueSheet &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        const char *get_media_catalog_number() const;
                        FLAC__uint64 get_lead_in() const;
                        bool get_is_cd() const;

                        unsigned get_num_tracks() const;
                        Track get_track(unsigned i) const;

                        void set_media_catalog_number(const char value[128]);
                        void set_lead_in(FLAC__uint64 value);
                        void set_is_cd(bool value);

                        void set_index(unsigned track_num, unsigned index_num, const ::FLAC__StreamMetadata_CueSheet_Index &index);

                        //! See FLAC__metadata_object_cuesheet_track_insert_index()
                        bool insert_index(unsigned track_num, unsigned index_num, const ::FLAC__StreamMetadata_CueSheet_Index &index);

                        //! See FLAC__metadata_object_cuesheet_track_delete_index()
                        bool delete_index(unsigned track_num, unsigned index_num);

                        //! See FLAC__metadata_object_cuesheet_set_track()
                        bool set_track(unsigned i, const Track &track);

                        //! See FLAC__metadata_object_cuesheet_insert_track()
                        bool insert_track(unsigned i, const Track &track);

                        //! See FLAC__metadata_object_cuesheet_delete_track()
                        bool delete_track(unsigned i);

                        //! See FLAC__metadata_object_cuesheet_is_legal()
                        bool is_legal(bool check_cd_da_subset = false, const char **violation = 0) const;

                        //! See FLAC__metadata_object_cuesheet_calculate_cddb_id()
                        FLAC__uint32 calculate_cddb_id() const;
                };

                /** PICTURE metadata block.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 *  and the <A HREF="../format.html#metadata_block_picture">format specification</A>.
                 */
                class FLACPP_API Picture : public Prototype {
                public:
                        Picture();

                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline Picture(const Picture &object): Prototype(object) { }
                        inline Picture(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline Picture(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Picture(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~Picture();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline Picture &operator=(const Picture &object) { Prototype::operator=(object); return *this; }
                        inline Picture &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline Picture &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Picture &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const Picture &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const Picture &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        ::FLAC__StreamMetadata_Picture_Type get_type() const;
                        const char *get_mime_type() const; // NUL-terminated printable ASCII string
                        const FLAC__byte *get_description() const; // NUL-terminated UTF-8 string
                        FLAC__uint32 get_width() const;
                        FLAC__uint32 get_height() const;
                        FLAC__uint32 get_depth() const;
                        FLAC__uint32 get_colors() const; ///< a return value of \c 0 means true-color, i.e. 2^depth colors
                        FLAC__uint32 get_data_length() const;
                        const FLAC__byte *get_data() const;

                        void set_type(::FLAC__StreamMetadata_Picture_Type type);

                        //! See FLAC__metadata_object_picture_set_mime_type()
                        bool set_mime_type(const char *string); // NUL-terminated printable ASCII string

                        //! See FLAC__metadata_object_picture_set_description()
                        bool set_description(const FLAC__byte *string); // NUL-terminated UTF-8 string

                        void set_width(FLAC__uint32 value) const;
                        void set_height(FLAC__uint32 value) const;
                        void set_depth(FLAC__uint32 value) const;
                        void set_colors(FLAC__uint32 value) const; ///< a value of \c 0 means true-color, i.e. 2^depth colors

                        //! See FLAC__metadata_object_picture_set_data()
                        bool set_data(const FLAC__byte *data, FLAC__uint32 data_length);
                };

                /** Opaque metadata block for storing unknown types.
                 *  This should not be used unless you know what you are doing;
                 *  it is currently used only internally to support forward
                 *  compatibility of metadata blocks.
                 *  See the \link flacpp_metadata_object overview \endlink for more,
                 */
                class FLACPP_API Unknown : public Prototype {
                public:
                        Unknown();
                        //
                        //@{
                        /** Constructs a copy of the given object.  This form
                         *  always performs a deep copy.
                         */
                        inline Unknown(const Unknown &object): Prototype(object) { }
                        inline Unknown(const ::FLAC__StreamMetadata &object): Prototype(object) { }
                        inline Unknown(const ::FLAC__StreamMetadata *object): Prototype(object) { }
                        //@}

                        /** Constructs an object with copy control.  See
                         *  Prototype(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Unknown(::FLAC__StreamMetadata *object, bool copy): Prototype(object, copy) { }

                        ~Unknown();

                        //@{
                        /** Assign from another object.  Always performs a deep copy. */
                        inline Unknown &operator=(const Unknown &object) { Prototype::operator=(object); return *this; }
                        inline Unknown &operator=(const ::FLAC__StreamMetadata &object) { Prototype::operator=(object); return *this; }
                        inline Unknown &operator=(const ::FLAC__StreamMetadata *object) { Prototype::operator=(object); return *this; }
                        //@}

                        /** Assigns an object with copy control.  See
                         *  Prototype::assign_object(::FLAC__StreamMetadata *object, bool copy).
                         */
                        inline Unknown &assign(::FLAC__StreamMetadata *object, bool copy) { Prototype::assign_object(object, copy); return *this; }

                        //@{
                        /** Check for equality, performing a deep compare by following pointers. */
                        inline bool operator==(const Unknown &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata &object) const { return Prototype::operator==(object); }
                        inline bool operator==(const ::FLAC__StreamMetadata *object) const { return Prototype::operator==(object); }
                        //@}

                        //@{
                        /** Check for inequality, performing a deep compare by following pointers. */
                        inline bool operator!=(const Unknown &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata &object) const { return Prototype::operator!=(object); }
                        inline bool operator!=(const ::FLAC__StreamMetadata *object) const { return Prototype::operator!=(object); }
                        //@}

                        const FLAC__byte *get_data() const;

                        //! This form always copies \a data
                        bool set_data(const FLAC__byte *data, unsigned length);
                        bool set_data(FLAC__byte *data, unsigned length, bool copy);
                };

                /* \} */


                /** \defgroup flacpp_metadata_level0 FLAC++/metadata.h: metadata level 0 interface
                 *  \ingroup flacpp_metadata
                 *
                 *  \brief
                 *  Level 0 metadata iterators.
                 *
                 *  See the \link flac_metadata_level0 C layer equivalent \endlink
                 *  for more.
                 *
                 * \{
                 */

                FLACPP_API bool get_streaminfo(const char *filename, StreamInfo &streaminfo); ///< See FLAC__metadata_get_streaminfo().

                FLACPP_API bool get_tags(const char *filename, VorbisComment *&tags); ///< See FLAC__metadata_get_tags().
                FLACPP_API bool get_tags(const char *filename, VorbisComment &tags); ///< See FLAC__metadata_get_tags().

                FLACPP_API bool get_cuesheet(const char *filename, CueSheet *&cuesheet); ///< See FLAC__metadata_get_cuesheet().
                FLACPP_API bool get_cuesheet(const char *filename, CueSheet &cuesheet); ///< See FLAC__metadata_get_cuesheet().

                FLACPP_API bool get_picture(const char *filename, Picture *&picture, ::FLAC__StreamMetadata_Picture_Type type, const char *mime_type, const FLAC__byte *description, unsigned max_width, unsigned max_height, unsigned max_depth, unsigned max_colors); ///< See FLAC__metadata_get_picture().
                FLACPP_API bool get_picture(const char *filename, Picture &picture, ::FLAC__StreamMetadata_Picture_Type type, const char *mime_type, const FLAC__byte *description, unsigned max_width, unsigned max_height, unsigned max_depth, unsigned max_colors); ///< See FLAC__metadata_get_picture().

                /* \} */


                /** \defgroup flacpp_metadata_level1 FLAC++/metadata.h: metadata level 1 interface
                 *  \ingroup flacpp_metadata
                 *
                 *  \brief
                 *  Level 1 metadata iterator.
                 *
                 *  The flow through the iterator in the C++ layer is similar
                 *  to the C layer:
                 *    - Create a SimpleIterator instance
                 *    - Check SimpleIterator::is_valid()
                 *    - Call SimpleIterator::init() and check the return
                 *    - Traverse and/or edit.  Edits are written to file
                 *      immediately.
                 *    - Destroy the SimpleIterator instance
                 *
                 *  The ownership of pointers in the C++ layer follows that in
                 *  the C layer, i.e.
                 *    - The objects returned by get_block() are yours to
                 *      modify, but changes are not reflected in the FLAC file
                 *      until you call set_block().  The objects are also
                 *      yours to delete; they are not automatically deleted
                 *      when passed to set_block() or insert_block_after().
                 *
                 *  See the \link flac_metadata_level1 C layer equivalent \endlink
                 *  for more.
                 *
                 * \{
                 */

                /** This class is a wrapper around the FLAC__metadata_simple_iterator
                 *  structures and methods; see the
                 * \link flacpp_metadata_level1 usage guide \endlink and
                 * ::FLAC__Metadata_SimpleIterator.
                 */
                class FLACPP_API SimpleIterator {
                public:
                        /** This class is a wrapper around FLAC__Metadata_SimpleIteratorStatus.
                         */
                        class FLACPP_API Status {
                        public:
                                inline Status(::FLAC__Metadata_SimpleIteratorStatus status): status_(status) { }
                                inline operator ::FLAC__Metadata_SimpleIteratorStatus() const { return status_; }
                                inline const char *as_cstring() const { return ::FLAC__Metadata_SimpleIteratorStatusString[status_]; }
                        protected:
                                ::FLAC__Metadata_SimpleIteratorStatus status_;
                        };

                        SimpleIterator();
                        virtual ~SimpleIterator();

                        bool is_valid() const; ///< Returns \c true iff object was properly constructed.

                        bool init(const char *filename, bool read_only, bool preserve_file_stats); ///< See FLAC__metadata_simple_iterator_init().

                        Status status();                                                    ///< See FLAC__metadata_simple_iterator_status().
                        bool is_writable() const;                                           ///< See FLAC__metadata_simple_iterator_is_writable().

                        bool next();                                                        ///< See FLAC__metadata_simple_iterator_next().
                        bool prev();                                                        ///< See FLAC__metadata_simple_iterator_prev().
                        bool is_last() const;                                               ///< See FLAC__metadata_simple_iterator_is_last().

                        off_t get_block_offset() const;                                     ///< See FLAC__metadata_simple_iterator_get_block_offset().
                        ::FLAC__MetadataType get_block_type() const;                        ///< See FLAC__metadata_simple_iterator_get_block_type().
                        unsigned get_block_length() const;                                  ///< See FLAC__metadata_simple_iterator_get_block_length().
                        bool get_application_id(FLAC__byte *id);                            ///< See FLAC__metadata_simple_iterator_get_application_id().
                        Prototype *get_block();                                             ///< See FLAC__metadata_simple_iterator_get_block().
                        bool set_block(Prototype *block, bool use_padding = true);          ///< See FLAC__metadata_simple_iterator_set_block().
                        bool insert_block_after(Prototype *block, bool use_padding = true); ///< See FLAC__metadata_simple_iterator_insert_block_after().
                        bool delete_block(bool use_padding = true);                         ///< See FLAC__metadata_simple_iterator_delete_block().

                protected:
                        ::FLAC__Metadata_SimpleIterator *iterator_;
                        void clear();
                };

                /* \} */


                /** \defgroup flacpp_metadata_level2 FLAC++/metadata.h: metadata level 2 interface
                 *  \ingroup flacpp_metadata
                 *
                 *  \brief
                 *  Level 2 metadata iterator.
                 *
                 *  The flow through the iterator in the C++ layer is similar
                 *  to the C layer:
                 *    - Create a Chain instance
                 *    - Check Chain::is_valid()
                 *    - Call Chain::read() and check the return
                 *    - Traverse and/or edit with an Iterator or with
                 *      Chain::merge_padding() or Chain::sort_padding()
                 *    - Write changes back to FLAC file with Chain::write()
                 *    - Destroy the Chain instance
                 *
                 *  The ownership of pointers in the C++ layer is slightly
                 *  different than in the C layer, i.e.
                 *    - The objects returned by Iterator::get_block() are NOT
                 *      owned by the iterator and should be deleted by the
                 *      caller when finished, BUT, when you modify the block,
                 *      it will directly edit what's in the chain and you do
                 *      not need to call Iterator::set_block().  However the
                 *      changes will not be reflected in the FLAC file until
                 *      the chain is written with Chain::write().
                 *    - When you pass an object to Iterator::set_block(),
                 *      Iterator::insert_block_before(), or
                 *      Iterator::insert_block_after(), the iterator takes
                 *      ownership of the block and it will be deleted by the
                 *      chain.
                 *
                 *  See the \link flac_metadata_level2 C layer equivalent \endlink
                 *  for more.
                 *
                 * \{
                 */

                /** This class is a wrapper around the FLAC__metadata_chain
                 *  structures and methods; see the
                 * \link flacpp_metadata_level2 usage guide \endlink and
                 * ::FLAC__Metadata_Chain.
                 */
                class FLACPP_API Chain {
                public:
                        /** This class is a wrapper around FLAC__Metadata_ChainStatus.
                         */
                        class FLACPP_API Status {
                        public:
                                inline Status(::FLAC__Metadata_ChainStatus status): status_(status) { }
                                inline operator ::FLAC__Metadata_ChainStatus() const { return status_; }
                                inline const char *as_cstring() const { return ::FLAC__Metadata_ChainStatusString[status_]; }
                        protected:
                                ::FLAC__Metadata_ChainStatus status_;
                        };

                        Chain();
                        virtual ~Chain();

                        friend class Iterator;

                        bool is_valid() const; ///< Returns \c true iff object was properly constructed.

                        Status status();                                                ///< See FLAC__metadata_chain_status().

                        bool read(const char *filename, bool is_ogg = false);                                ///< See FLAC__metadata_chain_read(), FLAC__metadata_chain_read_ogg().
                        bool read(FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, bool is_ogg = false);  ///< See FLAC__metadata_chain_read_with_callbacks(), FLAC__metadata_chain_read_ogg_with_callbacks().

                        bool check_if_tempfile_needed(bool use_padding);                ///< See FLAC__metadata_chain_check_if_tempfile_needed().

                        bool write(bool use_padding = true, bool preserve_file_stats = false); ///< See FLAC__metadata_chain_write().
                        bool write(bool use_padding, ::FLAC__IOHandle handle, ::FLAC__IOCallbacks callbacks); ///< See FLAC__metadata_chain_write_with_callbacks().
                        bool write(bool use_padding, ::FLAC__IOHandle handle, ::FLAC__IOCallbacks callbacks, ::FLAC__IOHandle temp_handle, ::FLAC__IOCallbacks temp_callbacks); ///< See FLAC__metadata_chain_write_with_callbacks_and_tempfile().

                        void merge_padding();                                           ///< See FLAC__metadata_chain_merge_padding().
                        void sort_padding();                                            ///< See FLAC__metadata_chain_sort_padding().

                protected:
                        ::FLAC__Metadata_Chain *chain_;
                        virtual void clear();
                };

                /** This class is a wrapper around the FLAC__metadata_iterator
                 *  structures and methods; see the
                 * \link flacpp_metadata_level2 usage guide \endlink and
                 * ::FLAC__Metadata_Iterator.
                 */
                class FLACPP_API Iterator {
                public:
                        Iterator();
                        virtual ~Iterator();

                        bool is_valid() const; ///< Returns \c true iff object was properly constructed.


                        void init(Chain &chain);                       ///< See FLAC__metadata_iterator_init().

                        bool next();                                   ///< See FLAC__metadata_iterator_next().
                        bool prev();                                   ///< See FLAC__metadata_iterator_prev().

                        ::FLAC__MetadataType get_block_type() const;   ///< See FLAC__metadata_iterator_get_block_type().
                        Prototype *get_block();                        ///< See FLAC__metadata_iterator_get_block().
                        bool set_block(Prototype *block);              ///< See FLAC__metadata_iterator_set_block().
                        bool delete_block(bool replace_with_padding);  ///< See FLAC__metadata_iterator_delete_block().
                        bool insert_block_before(Prototype *block);    ///< See FLAC__metadata_iterator_insert_block_before().
                        bool insert_block_after(Prototype *block);     ///< See FLAC__metadata_iterator_insert_block_after().

                protected:
                        ::FLAC__Metadata_Iterator *iterator_;
                        virtual void clear();
                };

                /* \} */

        }
}

#endif