vfs: check userland buffers before reading them.

[haiku.git] / docs / user / app / Message.dox

/*
 * Copyright 2007-2014 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Niels Sascha Reedijk, niels.reedijk@gmail.com
 *              John Scipione, jscpione@gmail.com
 *
 * Corresponds to:
 *              headers/os/app/Message.h        hrev47355
 *              src/kits/app/Message.cpp        hrev47355
 */


/*!
        \file Message.h
        \ingroup app
        \ingroup libbe
        \brief Provides the BMessage class.
*/


///// Name lengths and Scripting specifiers /////


/*!
        \def B_FIELD_NAME_LENGTH
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \def B_PROPERTY_NAME_LENGTH
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_NO_SPECIFIER
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_DIRECT_SPECIFIER
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_INDEX_SPECIFIER
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_REVERSE_INDEX_SPECIFIER,
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_RANGE_SPECIFIER
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_REVERSE_RANGE_SPECIFIER
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_NAME_SPECIFIER
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_ID_SPECIFIER
        \brief Undocumented...

        \since BeOS R3
*/


/*!
        \var B_SPECIFIERS_END
        \brief Undocumented...

        \since BeOS R3
*/


///// Class BMessage /////


/*!
        \class BMessage
        \ingroup app
        \ingroup libbe
        \brief A container that can be send and received using the Haiku messaging
               subsystem.

        This class is at the center of the web of messaging classes, in the sense
        that it defines the actual structure of the messages. Messages have two
        <b>important elements</b>: the #what identifier, and the data members. The
        first can be directly manipulated, the latter can be manipulated through
        AddData(), FindData() and ReplaceData() and their derivatives. Neither of
        these elements are mandatory.

        The second important role of BMessage is that it stores <b>meta data</b>:
        who sent the message and with what intention? The methods of BMessage will
        disclose if the message was a reply (IsReply()), where it came from
        (IsSourceRemote()), whether a reply is expected (IsSourceWaiting()), and in
        case the message is a reply, what it's a reply to (Previous()).

        Mostly, messages are used to pass information between the the objects in
        your application, but because messages are such flexible data containers,
        they are also often used for other <b>data storage purposes</b>. Many
        applications store their settings as messages. Because messages can be
        flattened to data streams (such as files), they provide an easy but
        powerful tool for data storage.

        All methods can be classified in these areas:
        - Adding, Finding, Replacing and Removing Data.
        - Statistics and Miscellaneous information.
        - Delivery information.
        - Utilities to reply to messages.

        To see how messages fit in with the greater picture, have a look at the
        \ref app_messaging "Messaging Introduction".

        \since BeOS R3
*/


/*!
        \var BMessage::what
        \brief A 4-byte constant that determines the type of message.

        You can directly manipulate this data member.

        \since BeOS R3
*/


/*!
        \fn BMessage::BMessage()
        \brief Construct an empty message, without any data members and with a
               \a what constant set to \c 0.

        \see BMessage(uint32 what)
        \see BMessage(const BMessage& other)

        \since BeOS R3
*/


/*!
        \fn BMessage::BMessage(uint32 what)
        \brief Construct an empty message with the \a what member set to the
               specified value.

        \see BMessage::BMessage()
        \see BMessage::BMessage(const BMessage& other)

        \since BeOS R3
*/


/*!
        \fn BMessage::BMessage(const BMessage& other)
        \brief Construct a new message that is a copy of another message.

        The \a what member and the data values are copied. The metadata, such as
        whether or not the message is a drop message or reply information is
        not copied. If the original message is a reply to a previous message
        this will make IsReply() return \c true, while calling the same method on
        a copy of the message will return \c false.

        \remark BeOS kept the metadata of the message while Haiku deviates from
                this behavior. Use the Haiku implementation of message copying
                as the default behavior to keep your applications backwards
                compatible.

        \see BMessage::BMessage()
        \see BMessage(uint32 what)

        \since BeOS R3
*/


/*!
        \fn BMessage::~BMessage()
        \brief Free the data members associated with the message.

        If there still is a sender waiting for a reply, the \c B_NO_REPLY message
        will be sent to inform them that there won't be a reply.

        \since BeOS R3
*/


/*!
        \name Statistics and Miscellaneous Information
*/


//! @{


/*!
        \fn status_t BMessage::GetInfo(type_code typeRequested, int32 index,
                char** nameFound, type_code* typeFound, int32* countFound) const
        \brief Retrieve the name, the type and the number of items in a message by
               an \a index.

        \param[in] typeRequested If you want to limit the search to only one type,
                   pass that type code here. If you don't care which type the data
                   has, you can pass \c B_ANY_TYPE.
        \param[in] index The index of the data you want to investigate.
        \param[out] nameFound The name of the item if it is found. Haiku will fill
                    in a pointer to the internal name buffer in the message. This
                    means that you should not manipulate this name. If you are not
                    interested in the name, you can safely pass \c NULL.
        \param[out] typeFound The type of the item at \a index. If you are
                    not interested in the type (because you specifically asked for
                    a type), you can safely pass \c NULL.
        \param[out] countFound The number of items at \a index. If data
                    items have the same name, they will be placed under the same
                    index.

        \return If the \a index is found, and matches the requested type,
                then the other parameters will be filled in. If this is not the
                case, the method will return with an error.
        \retval B_OK An match was found. The values have been filled in.
        \retval B_BAD_INDEX The \a index was out of range. None of the
                passed variables have been altered.
        \retval B_BAD_TYPE The data field at \a index does not have the
                requested type.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::GetInfo(const char* name, type_code* typeFound,
                int32* countFound) const
        \brief Retrieve the type and the number of data items in this message that
               are associated with a \a name.

        \param[in] name The name of the data member that you are looking for.
        \param[out] typeFound In case of a match, the name of the data member will
                    be put in this parameter. In case you are not interested, you
                    can pass \c NULL.
        \param[out] countFound In case of a match, the number of items at this
                    label will be in this parameter. In case you are not
                    interested, you can safely pass \c NULL.

        \return If the message has data associated with the given \a name,
                the other parameters will contain information associated with the
                data, else, the method will return with an error.
        \retval B_OK A match was found. The other parameters have been filled in.
        \retval B_BAD_VALUE You passed \c NULL as argument to \a name.
        \retval B_NAME_NOT_FOUND There is no data with the label \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::GetInfo(const char* name, type_code* typeFound,
                bool* fixedSize) const
        \brief Retrieve the type and whether or not the size of the data is fixed
                associated with a \a name.

        This method is the same as GetInfo(const char*, type_code*, int32*) const,
        with the difference that you can find out whether or not the size of the
        data associated with the \a name is fixed. You will get this value
        in the variable you passed as \a fixedSize parameter.

        \since BeOS R4
*/


/*!
        \fn int32 BMessage::CountNames(type_code type) const
        \brief Count the number of names of a certain \a type.

        This method can be used to count the number of items of a certain type.
        It's practical use is limited to debugging purposes.

        \param type The type you want to find. If you pass \c B_ANY_TYPE, this
               method will return the total number of data items.

        \return The number of data items in this message with the specified
                \a type, or \c 0 in case no items match the type.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::IsEmpty() const
        \brief Check if the message has data members.

        \return If this message contains data members, this method will return
                \c true, else it will return \c false.

        \see MakeEmpty()

        \since BeOS R3
*/


/*!
        \fn bool BMessage::IsSystem() const
        \brief Check if the message is a system message.

        \return If this message is a system message, the method will return
                \c true.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::IsReply() const
        \brief Check if the message is a reply to a (previous) message.

        \return If this message is a reply, this method will return \c true.

        \since BeOS R3
*/


/*!
        \fn void BMessage::PrintToStream() const
        \brief Print the message to the standard output.

        This method can be used to debug your application. It can be used to check
        if it creates the messages properly, by checking if all the required fields
        are present, and it can be used to debug your message handling routines,
        especially the handling of those that are sent by external applications, to
        see if you understand the semantics correctly.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::Rename(const char* oldEntry, const char* newEntry)
        \brief Rename a data label.

        \param oldEntry The name of the label you want to rename.
        \param newEntry The new name of the data entry.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK Renaming succeeded.
        \retval B_BAD_VALUE Either the \a oldEntry or the
                \a newEntry pointers are \c NULL.
        \retval B_NAME_NOT_FOUND There is no data associated with the label
                \a oldEntry.

        \since Haiku R1
*/


//! @}


/*!
        \name Delivery Info
*/


//! @{


/*!
        \fn bool BMessage::WasDelivered() const
        \brief Check if this message was delivered through the delivery methods.

        If this message is passed via a BMessenger or BLooper::PostMessage(), this
        method will return \c true.

        \warning This method should not be abused by a thread that sends a message
                 to track whether or not a message was delivered. This is because
                 the ownership of the message goes to the receiving looper, which
                 will delete the message as soon as it is done with it.

        \warning If you need to check whether a message is delivered, you should
                 either ask for a reply, or use one of the synchronous
                 BMessenger::SendMessage() methods.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::IsSourceWaiting() const
        \brief Check if the sender expects a reply.

        This method will return \c true, if the sender flagged that it is waiting
        for a reply, and such a reply has not yet been sent.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::IsSourceRemote() const
        \brief Check if the message is sent by another application.

        \since BeOS R3
*/


/*!
        \fn BMessenger BMessage::ReturnAddress() const
        \brief Get a messenger that points to the sender of the message.

        Using this method, you can fetch a BMessenger that can be used to deliver
        replies to this message. This method works both for local and remote
        deliveries.

        For remote deliveries, this approach is preferred over sending the reply
        using a standard BMessenger that is created with the signature of the
        application. A standard BMessenger sends the messages to the main BLooper
        of the application, the BApplication object. With the delivery data stored
        in the messages, the reply using this messenger will be directed at a
        specific looper that is able to handle the replies.

        If this method is called on a message that has not been delivered (yet),
        it will return an empty BMessenger object.

        \since BeOS R3
*/


/*!
        \fn const BMessage* BMessage::Previous() const
        \brief Get the message to which this message is a reply.

        \return Returns a new BMessage with the same data stuctures as the message
                to which this message is a reply. You get the ownership of this
                message, so free it when you're done. If this message isn't a
                reply to another message, this method will return \c NULL.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::WasDropped() const
        \brief Check if the message was delivered through 'drag and drop'.

        \return This method returns \c true if the message has been delivered
                through drag and drop. It returns \c false if it has been delivered
                through the regular messaging functions, or if the message has not
                been delivered at all.

        \see DropPoint()

        \since BeOS R3
*/


/*!
        \fn BPoint BMessage::DropPoint(BPoint* offset) const
        \brief Get the coordinates of the drop point of the message.

        If the message has been delivered because of drag and drop, which can be
        verified with the WasDropped() method, this method will return a BPoint to
        where exactly the drop off was made.

        Because drop messages are delivered to the BWindow in which they were
        dropped, and BWindow is a subclass of BLooper, you can use BWindow to
        determine based on the location, how you should react to it.

        If this message was not delivered through drag and drop, it will return
        a \c NULL pointer.

        \see WasDropped()

        \since BeOS R3
*/


//! @}


/*!
        \name Replying
*/


//! @{


/*!
        \fn status_t BMessage::SendReply(uint32 command, BHandler* replyTo)
        \brief Asynchronously send a reply to this message.

        This is an overloaded member of
        SendReply(BMessage*, BMessenger, bigtime_t). Use this variant if you
        want to send a message without data members.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::SendReply(BMessage* reply, BHandler* replyTo,
                bigtime_t timeout)
        \brief Asynchronously send a reply to this message.

        This is an overloaded member of SendReply(BMessage*, BMessenger, bigtime_t).
        Use this variant if you want to send the message to a specific handler
        (instead of a complete messenger).

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::SendReply(BMessage* reply, BMessenger replyTo,
                bigtime_t timeout)
        \brief Asynchronously send a reply to this message.

        This method sends a reply to this message to the sender. On your turn,
        you specify a messenger that handles a reply back to the message you
        specify as the \a reply argument. You can set a timeout for the
        message to be delivered. This method blocks until the message has been
        received, or the \a timeout has been reached.

        \param reply The message that is in reply to this message.
        \param replyTo In case the receiver needs to reply to the message you are
               sending, you can specify the return address with this argument.
        \param timeout The maximum time in microseconds this delivery may take. The
               \a timeout is a relative timeout. You can also use
               \c B_INFINITE_TIMEOUT if you want to wait infinitely for the message
               to be delivered.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The message has been delivered.
        \retval B_DUPLICATE_REPLY There already has been a reply to this message.
        \retval B_BAD_PORT_ID The reply address is not valid (anymore).
        \retval B_WOULD_BLOCK The delivery \a timeout was
                \c B_INFINITE_TIMEOUT (\c 0) and the target port was full when
                trying to deliver the message.
        \retval B_TIMED_OUT The timeout expired while trying to deliver the
                message.

        \see SendReply(uint32 command, BHandler* replyTo)

        \since Haiku R1
*/


/*!
        \fn status_t BMessage::SendReply(uint32 command, BMessage* replyToReply)
        \brief Synchronously send a reply to this message, and wait for a reply
               back.

        This is an overloaded member of
        SendReply(BMessage*, BMessage*, bigtime_t, bigtime_t)
        Use this variant if you want to send a message without data members.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::SendReply(BMessage* reply, BMessage* replyToReply,
                bigtime_t sendTimeout, bigtime_t replyTimeout)
        \brief Synchronously send a reply to this message, and wait for a reply
               back.

        This method sends a reply to this message to the sender. The
        \a reply is delivered, and then the method waits for a reply from
        the receiver. If a reply is received, that reply is copied into the
        \a replyToReply argument.
        If the message was delivered properly, but the receiver did not reply
        within the specified \a replyTimeout, the \a what member of
        \a replyToReply will be set to \c B_NO_REPLY.

        \param reply The message that is in reply to this message.
        \param[out] replyToReply The reply is copied into this argument.
        \param sendTimeout The maximum time in microseconds this delivery may take.
               The \a timeout is a relative timeout. You can also use
               \c B_INFINITE_TIMEOUT if you want to wait infinitely for the message
               to be delivered.
        \param replyTimeout The maximum time in microseconds you want to wait for a
               reply. Note that the timer starts when the message has been
               delivered.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The message has been delivered.
        \retval B_DUPLICATE_REPLY There already has been a reply to this message.
        \retval B_BAD_VALUE Either \a reply or \a replyToReply is \c NULL.
        \retval B_BAD_PORT_ID The reply address is not valid (anymore).
        \retval B_WOULD_BLOCK The delivery \a timeout was
                \c B_INFINITE_TIMEOUT (\c 0) and the target port was full when
                trying to deliver the message.
        \retval B_TIMED_OUT The timeout expired while trying to deliver the
                message.
        \retval B_NO_MORE_PORTS All reply ports are in use.

        \see SendReply(uint32 command, BMessage* replyToReply)

        \since BeOS R3
*/


//! @}


/*!
        \name Flattening

        Because of historical reasons and for binary compatibility, this class
        provides a flattening API without inheriting the BFlattenable class. The
        API is more or less the same, but you are inconvenienced when you want to
        use messages in methods that handle BFlattenable objects.
*/


//! @{


/*!
        \fn ssize_t BMessage::FlattenedSize() const
        \brief Return the size in bytes required when you want to flatten this
               message to a stream of bytes.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::Flatten(char* buffer, ssize_t size) const
        \brief Flatten the message to a \a buffer.

        \param buffer The buffer to write the data to.
        \param size The size of the buffer.

        \return \c B_OK in case of success, or an error code in case something
                went awry.

        \warning Make sure the buffer is large enough to hold the message. This
                 method does not double-check for you!

        \see FlattenedSize()
        \see Flatten(BDataIO* stream, ssize_t* size) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::Flatten(BDataIO* stream, ssize_t* size) const
        \brief Flatten the message to a \a stream.

        \param[in]  stream The stream to flatten the message to.
        \param[out] size The method writes the number of bytes actually written
                    to this argument.
        \return \c B_OK in case of success, or an error code in case something
                went awry.

        \warning Make sure the subclass of the BDataIO interface either protects
                 against buffer overwrites, or check if the number of bytes that
                 is going to be written isn't larger than it can handle.

        \see FlattenedSize()
        \see Flatten(char* buffer, ssize_t size) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::Unflatten(const char* flatBuffer)
        \brief Unflatten a message from a buffer and put it into the current
               object.

        This action clears the current contents of the message.

        \param flatBuffer The buffer that contains the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The buffer has been unflattened.
        \retval B_BAD_VALUE The buffer does not contain a valid message.
        \retval B_NO_MEMORY An error occured whilst allocating memory for the data
                members.

        \see Flatten(char* buffer, ssize_t size) const
        \see Unflatten(BDataIO* stream)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::Unflatten(BDataIO* stream)
        \brief Unflatten a message from a stream and put it into the current
               object.

        This action clears the current contents of the message.

        \param stream The stream that contains the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The message has been unflattened.
        \retval B_BAD_VALUE The stream does not contain a valid message.
        \retval B_NO_MEMORY An error occured whilst allocating memory for the
                data members.

        \see Flatten(BDataIO* stream, ssize_t* size) const
        \see Unflatten(const char*)

        \since BeOS R3
*/


//! @}


/*!
        \name Specifiers (Scripting)
*/


//! @{


/*!
        \fn status_t BMessage::AddSpecifier(const char* property)
        \brief Undocumented.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddSpecifier(const char* property, int32 index)
        \brief Undocumented.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddSpecifier(const char* property, int32 index,
                int32 range)
        \brief Undocumented.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddSpecifier(const char* property, const char* name)
        \brief Undocumented.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddSpecifier(const BMessage* specifier)
        \brief Undocumented.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::SetCurrentSpecifier(int32 index)
        \brief Undocumented.

        \since Haiku R1
*/


/*!
        \fn status_t BMessage::GetCurrentSpecifier(int32* index,
                BMessage* specifier, int32* what, const char** property) const
        \brief Undocumented.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasSpecifiers() const
        \brief Undocumented.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::PopSpecifier()
        \brief Undocumented.

        \since BeOS R3
*/


//! @}


/*!
        \name Adding Data
*/


//! @{


/*!
        \fn status_t BMessage::AddData(const char* name, type_code type,
                const void* data, ssize_t numBytes, bool isFixedSize, int32 count)
        \brief Add \a data of a certain \a type to the message.

        The amount of \a numBytes is copied into the message. The data is
        stored at the label specified in \a name. You are responsible for
        specifying the correct \a type. The Haiku API already specifies
        many constants, such as \c B_FLOAT_TYPE or \c B_RECT_TYPE. See
        TypeConstants.h for more information on the system-wide defined types.

        If the field with the \a name already exists, the data is added in
        an array-like form. If you are adding a certain \a name for the
        first time, you are able to specify some properties of this array. You can
        fix the size of each data entry, and you can also instruct BMessage to
        allocate a \a count of items. The latter does not mean that the
        number of items is fixed; the array will grow nonetheless. Also, note that
        every \a name can only be associated with one \a type of
        data.

        If consecutive method calls specify a different \a type than the
        initial, these calls will fail.

        There is no limit to the number of labels, or the amount of data, but
        note that searching of data members is linear, as well as that some
        messages will be copied whilst being passed around, so if the amount of
        data you need to pass is too big, find another way to pass it.

        \param name The label to which this data needs to be associated. If the
               \a name already exists, the new data will be added in an
               array-like style.
        \param type The type of data. If you are adding data to the same
        \a name, make sure it is the same type.
        \param data The data buffer to copy the bytes from.
        \param numBytes The number of bytes to be copied. If this is the first
               call to this method for this type of data, and you set
               \a isFixedSize to \c true, this will specify the size of all
               consecutive calls to this method.
        \param isFixedSize If this is the first call to this method with this
               \a name, you can specify the whether or not all items in this
               array should have the same fixed size.
        \param count If this is the first call to this method with this
               \a name, you can instruct this message to allocate a number of
               items in advance. This does not limit the amount of items though.
               The array will grow if needed.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The \a data is succesfully added.
        \retval B_BAD_VALUE The \a numBytes is less than, or equal to \c 0,
                or the size of this item is larger than the \a name allows,
                since it has been specified to have a fixed size.
        \retval B_ERROR There was an error whilst creating the label with
                your \a name.
        \retval B_BAD_TYPE The \a type you specified is different than the
                one already associated with \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddRect(const char* name, BRect aRect)
        \brief Convenience method to add a BRect to the label \a name.

        This method calls AddData() with the \c B_RECT_TYPE \a type.

        \param name The label to associate the data with.
        \param aRect The rectangle to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindRect()
        \see GetRect()
        \see ReplaceRect()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddPoint(const char* name, BPoint aPoint)
        \brief Convenience method to add a BPoint to the label \a name.

        This method calls AddData() with the \c B_POINT_TYPE \a type.

        \param name The label to associate the data with.
        \param aPoint The point to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindPoint()
        \see GetPoint()
        \see ReplacePoint()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddString(const char* name, const char* aString)
        \brief Convenience method to add a C-string to the label \a name.

        This method calls AddData() with the \c B_STRING_TYPE \a type.

        \param name The label to associate the data with.
        \param aString The string to copy to the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindString()
        \see GetString()
        \see ReplaceString()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddString(const char* name, const BString& aString)
        \brief Convenience method to add a BString to the label \a name.

        This method calls AddData() with the \c B_STRING_TYPE \a type.

        \param name The label to associate the data with.
        \param aString The string to copy to the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindString()
        \see GetString()
        \see ReplaceString()

        \since BeOS R5
*/


/*!
        \fn status_t BMessage::AddInt8(const char* name, int8 value)
        \brief Convenience method to add an \c int8 to the label \a name.

        This method calls AddData() with the \c B_INT8_TYPE \a type.

        \param name The label to associate the data with.
        \param value The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindInt8()
        \see GetInt8()
        \see ReplaceInt8()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddInt16(const char* name, int16 value)
        \brief Convenience method to add an \c int16 to the label \a name.

        This method calls AddData() with the \c B_INT16_TYPE \a type.

        \param name The label to associate the data with.
        \param value The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindInt16()
        \see GetInt16()
        \see ReplaceInt16()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddInt32(const char* name, int32 value)
        \brief Convenience method to add an \c int32 to the label \a name.

        This method calls AddData() with the \c B_INT32_TYPE \a type.

        \param name The label to associate the data with.
        \param value The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindInt32()
        \see GetInt32()
        \see ReplaceInt32()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddInt64(const char* name, int64 value)
        \brief Convenience method to add an \c int64 to the label \a name.

        This method calls AddData() with the \c B_INT64_TYPE \a type.

        \param name The label to associate the data with.
        \param value The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindInt64()
        \see GetInt64()
        \see ReplaceInt64()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddBool(const char* name, bool aBoolean)
        \brief Convenience method to add a \c bool to the label \a name.

        This method calls AddData() with the \c B_BOOL_TYPE \a type.

        \param name The label to associate the data with.
        \param aBoolean The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindBool()
        \see GetBool()
        \see ReplaceBool()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddFloat(const char* name, float aFloat)
        \brief Convenience method to add a \c float to the label \a name.

        This method calls AddData() with the \c B_FLOAT_TYPE \a type.

        \param name The label to associate the data with.
        \param aFloat The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindFloat()
        \see GetFloat()
        \see ReplaceFloat()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddDouble(const char* name, double aDouble)
        \brief Convenience method to add a \c double to the label \a name.

        This method calls AddData() with the \c B_DOUBLE_TYPE \a type.

        \param name The label to associate the data with.
        \param aDouble The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindDouble()
        \see GetDouble()
        \see ReplaceDouble()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddColor(const char* name, rgb_color aColor)
        \brief Convenience method to add a \c rgb_color to the label \a name.

        This method calls AddData() with the \c B_RGB_32_BIT_TYPE \a type.

        \param name The label to associate the data with.
        \param aColor The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddColor() for a more detailed overview of the inner workings.
        \see FindColor()
        \see GetColor()
        \see ReplaceColor()

        \since Haiku R1
*/


/*!
        \fn status_t BMessage::AddPointer(const char* name, const void* aPointer)
        \brief Convenience method to add a \c pointer to the label \a name.

        This method calls AddData() with the \c B_POINTER_TYPE \a type.

        \warning If you want to share objects between applications, remember
                 that each application has its own address space, and that it
                 therefore is useless to try to pass around objects by sending
                 pointers in messages. You should think about copying the
                 entire object in the message, or you should consider using
                 shared memory.

        \param name The label to associate the data with.
        \param aPointer The value to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindPointer()
        \see ReplacePointer()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddMessenger(const char* name, BMessenger messenger)
        \brief Convenience method to add a messenger to the label \a name.

        This method calls AddData() with the \c B_MESSENGER_TYPE \a type.

        \param name The label to associate the data with.
        \param messenger The messenger to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindMessenger()
        \see ReplaceMessenger()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddRef(const char* name, const entry_ref* ref)
        \brief Convenience method to add an \c entry_ref to the label
               \a name.

        This method calls AddData() with the \c B_REF_TYPE \a type.

        \param name The label to associate the data with.
        \param ref The reference to store in the message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindRef()
        \see ReplaceRef()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddMessage(const char* name,
                const BMessage* message)
        \brief Convenience method to add a message to the label \a name.

        This method calls AddData() with the \c B_MESSAGE_TYPE \a type.

        \param name The label to associate the data with.
        \param message The message to store in this message.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindMessage()
        \see ReplaceMessage()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::AddFlat(const char* name, BFlattenable* object,
                int32 count = 1)
        \brief Convenience method to add a flattenable to the label \a name.

        This method uses BFlattenable::TypeCode() to determine the type. It also
        uses BFlattenable::IsFixedSize() to determine whether or not the size of
        the object is supposedly always the same. You can specify a
        \a count, to pre-allocate more entries if you are going to add
        more than one of this type.

        \param name The label to associate the data with.
        \param object The object to flatten into the message.
        \param count The number of items to pre-allocate associated with this
               \a name.

        \returns A status code, \c B_OK on success or an error code.

        \see AddData() for a more detailed overview of the inner workings.
        \see FindFlat()
        \see ReplaceFlat()

        \since BeOS R3
*/


//! @}


/*!
        \name Removing Data
*/


//! @{


/*!
        \fn status_t BMessage::RemoveData(const char* name, int32 index)
        \brief Remove data associated with \a name at a specified
               \a index.

        If this is the only instance of the data, then the entire label will be
        removed. This means you can recreate it with another type.

        \param name The \a name of which the associated data should be cleared.
        \param index The \a index of the item that should be cleared.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The data has been removed.
        \retval B_BAD_VALUE The \a index is less than \c 0.
        \retval B_BAD_INDEX The \a index is out of bounds.
        \retval B_NAME_NOT_FOUND The \a name does not have any data associated
                with it.

        \see RemoveName()
        \see MakeEmpty()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::RemoveName(const char* name)
        \brief Remove all data associated with a \a name.

        This also removes the label, so that you can recreate it with another type,
        if you want to.

        \param name The \a name that refers to the data you want to clear out.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK All the data is removed.
        \retval B_BAD_VALUE The \a name pointer points to \c NULL.
        \retval B_NAME_NOT_FOUND The \a name does not exist in this message.

        \see RemoveData()
        \see MakeEmpty()

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::MakeEmpty()
        \brief Clear all data and metadata in this message.

        Everything is cleared out, all labels and all associated data, as well
        as metadata such as reply info.

        \return This method always returns \c B_OK.

        \see RemoveData()
        \see RemoveName()

        \since BeOS R3
*/


//! @}


/*!
        \name Finding Data

        Look at FindData() for a general introduction to finding data.
*/

/* TODO:
        Quick overview:

        <table>
                <tr><th>Type of data</th><th>Type code</th><th>Method</td></tr>
                <tr><td>BRect</td><td>\c B_RECT_TYPE</td><td>FindRect()</td></tr>
        </table>
*/


//! @{


/*!
        \fn status_t BMessage::FindData(const char* name, type_code type,
                int32 index, const void** data, ssize_t* numBytes) const
        \brief Find \a data that is stored in this message at an
               \a index.

        This method matches the label \a name with the \a type you
        are asking for, and it looks for the data that is stored at a certain
        \a index number. If all these things match, you will get a pointer
        to the internal buffer, and the method will put the size of the item in
        \a numBytes.

        Note that only this method, and FindString(const char*, const char**),
        pass a pointer to the internal buffer. The other more specific methods,
        such as FindBool() and FindRect() copy the data into a buffer you specify.
        This means that the data retrieved with this method is valid until the
        message is deleted.

        \param name The label the data should be associated with.
        \param type The type of data you want to retrieve. You can pass
               \c B_ANY_TYPE if you don't mind which type the data is.
        \param index The index in the array of the data that you want to retrieve.
               Note that the array is zero-based.
        \param[out] data A pointer to a pointer where the data can point to.
        \param[out] numBytes The size of the data will be put in this parameter.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The \a name was found, matches the type, and the data
                at \a index has been put in \a data.
        \retval B_BAD_VALUE One of the output arguments were \c NULL.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see status_t FindData(const char*, type_code, int32,
                const void**, ssize_t*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindData(const char* name, type_code type,
                const void** data, ssize_t* numBytes) const
        \brief Find \a data that is stored in this message.

        This is an overloaded version of
        FindData(const char*, type_code, int32, const void**, ssize_t*) const
        where data is sought at \a index \c 0.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindRect(const char* name, BRect* rect) const
        \brief Find a rectangle at the label \a name.

        This is an overloaded version of
        FindRect(const char*, int32, BRect*) const
        where the data is sought at \a index \c 0.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindRect(const char* name, int32 index,
                BRect* rect) const
        \brief Find a rectangle at the label \a name at an \a index.

        This method looks for the data with the \c B_RECT_TYPE, and copies it into
        a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param rect The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindRect(const char*, BRect*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindPoint(const char* name, BPoint* point) const
        \brief Find a point at the label \a name.

        This is an overloaded version of
        FindPoint(const char*, int32, BPoint*) const
        where the data is sought at \a index \c 0.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindPoint(const char* name, int32 index,
                BPoint* point) const
        \brief Find a point at the label \a name at an \a index.

        This method looks for the data with the \c B_POINT_TYPE, and copies it into
        a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param point The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindPoint(const char*, BPoint*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindString(const char* name,
                const char** string) const
        \brief Find a string at the label \a name.

        This is an overloaded version of
        FindString(const char*, int32, const char**) const
        where the data is sought at \a index \c 0.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindString(const char* name, int32 index,
                const char** string) const
        \brief Find a string at the label \a name at an \a index.

        This method looks for the data with the \c B_STRING_TYPE, and returns a
        pointer to the internal buffer of the message. Note that this pointer is
        valid, until the message is deleted.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param string The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindString(const char*, const char**) const
        \see FindString(const char*, int32, BString*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindString(const char* name, BString* string) const
        \brief Find a string at the label \a name.

        This is an overloaded version of
        FindString(const char*, int32, BString*) const
        where the data is sought at \a index \c 0.

        \since BeOS R5
*/


/*!
        \fn status_t BMessage::FindString(const char* name, int32 index,
                BString* string) const
        \brief Find a string at the label \a name at an \a index.

        This method looks for the data with the \c B_STRING_TYPE, and copies it
        into the \a string object.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param string The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindString(const char*, BString*) const
        \see FindString(const char*, int32, const char**) const

        \since BeOS R5
*/


/*!
        \fn status_t BMessage::FindInt8(const char* name, int8* value) const
        \brief Find an integer at the label \a name.

        This is an overloaded version of
        FindInt8(const char*, int32, int8*) const
        where the data is sought at \a index \c 0.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindInt8(const char* name, int32 index,
                int8* value) const
        \brief Find an integer at the label \a name at an \a index.

        This method looks for the data with the \c B_INT8_TYPE, and copies it into
        a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindInt8(const char*, int8*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindInt16(const char* name, int16* value) const
        \brief Find an integer at the label \a name.

        This is an overloaded version of FindInt8(const char*, int32, int16*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindInt16(const char* name, int32 index,
                int16* value) const
        \brief Find an integer at the label \a name at an \a index.

        This method looks for the data with the \c B_INT16_TYPE, and copies it into
        a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindInt16(const char*, int16*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindInt32(const char* name, int32* value) const
        \brief Find an integer at the label \a name.

        This is an overloaded version of
        FindInt32(const char*, int32, int32*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindInt32(const char* name, int32 index,
                int32* value) const
        \brief Find an integer at the label \a name at an \a index.

        This method looks for the data with the \c B_INT32_TYPE, and copies
        it into a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindInt32(const char*, int32*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindInt64(const char* name, int64* value) const
        \brief Find an integer at the label \a name.

        This is an overloaded version of
        FindInt64(const char*, int32, int64*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindInt64(const char* name, int32 index,
                int64* value) const
        \brief Find an integer at the label \a name at an \a index.

        This method looks for the data with the \c B_INT64_TYPE, and copies
        it into a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindInt64(const char*, int64*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindBool(const char* name, bool* value) const
        \brief Find a boolean at the label \a name.

        This is an overloaded version of
        FindBool(const char*, int32, bool*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindBool(const char* name, int32 index,
                bool* value) const
        \brief Find a boolean at the label \a name at an \a index.

        This method looks for the data with the \c B_BOOL_TYPE, and copies it into
        a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindBool(const char*, bool*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindFloat(const char* name, float* value) const
        \brief Find a float at the label \a name.

        This is an overloaded version of
        FindFloat(const char*, int32, float*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindFloat(const char* name, int32 index,
                float* value) const
        \brief Find a float at the label \a name at an \a index.

        This method looks for the data with the \c B_FLOAT_TYPE, and copies
        it into a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindFloat(const char*, float*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindDouble(const char* name, double* value) const
        \brief Find a double at the label \a name.

        This is an overloaded version of
        FindDouble(const char*, int32, double*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindDouble(const char* name, int32 index,
                double* value) const
        \brief Find a double at the label \a name at an \a index.

        This method looks for the data with the \c B_DOUBLE_TYPE, and copies it into
        a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindDouble(const char*, double*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindColor(const char* name, rgb_color* value) const
        \brief Find a color with the label \a name.

        This is an overloaded version of
        FindColor(const char*, int32, rgb_color*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since Haiku R1
*/


/*!
        \fn status_t BMessage::FindColor(const char* name, int32 index,
                rgb_color* value) const
        \brief Find a color at the label \a name at an \a index.

        This method looks for the data with the \c B_RGB_32_BIT_TYPE, and copies
        it into a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param value The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindColor(const char*, rgb_color*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindPointer(const char* name, void** pointer) const
        \brief Find a pointer at the label \a name.

        This is an overloaded version of
        FindPointer(const char*, int32, void*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param pointer The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindPointer(const char* name, int32 index,
                void** pointer) const
        \brief Find a pointer at the label \a name at an \a index.

        This method looks for the data with the \c B_POINTER_TYPE, and copies
        it into a provided buffer.

        \warning If you want to share objects between applications, remember
                 that each application has its own address space, and that it
                 therefore is useless to try to pass around objects by sending
                 pointers in messages. You should think about copying the entire
                 object in the message, or you should consider using shared memory.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param pointer The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindPointer(const char*, void*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindMessenger(const char* name,
                BMessenger* messenger) const
        \brief Find a messenger at the label \a name.

        This is an overloaded version of
        FindMessenger(const char*, int32, BMessenger*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param messenger The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindMessenger(const char* name, int32 index,
                BMessenger* messenger) const
        \brief Find a messenger at the label \a name at an \a index.

        This method looks for the data with the \c B_MESSENGER_TYPE, and copies it
        into a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param messenger The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindMessenger(const char*, BMessenger*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindRef(const char* name, entry_ref* ref) const
        \brief Find a reference to a file at the label \a name.

        This is an overloaded version of
        FindRef(const char*, int32, entry_ref*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param ref The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindRef(const char* name, int32 index,
                entry_ref* ref) const
        \brief Find a reference to a file at the label \a name at an
               \a index.

        This method looks for the data with the \c B_REF_TYPE, and copies it into
        a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param ref The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindRef(const char*, entry_ref*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindMessage(const char* name,
                BMessage* message) const
        \brief Find a message at the label \a name.

        This is an overloaded version of
        FindMessage(const char*, int32, BMessage*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param message The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindMessage(const char* name, int32 index,
                BMessage* message) const
        \brief Find a message at the label \a name at an \a index.

        This method looks for the data with the \c B_MESSAGE_TYPE, and
        copies it into a provided buffer.

        \param name The label to which the data is associated.
        \param index The index from which the data should be copied.
        \param message The object in which the data should be copied.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindMessage(const char*, BMessage*) const

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindFlat(const char* name,
                BFlattenable* object) const
        \brief Find a flattened object at the label \a name.

        This is an overloaded version of
        FindFlat(const char*, int32, BFlattenable*) const
        where the data is sought at \a index \c 0.

        \param name The label to which the data is associated.
        \param object The object in which the data should be unflattened.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::FindFlat(const char* name, int32 index,
                BFlattenable* object) const
        \brief Find a flattened object at the label \a name at an
               \a index.

        The type is determined by the type of the passed object. If that type is
        available at the specified label, then the Unflatten() method of that
        object will be called.

        \param name The label to which the data is associated.
        \param index The index from which the data should be unflattened.
        \param object The object in which the data should be unflattened.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_BAD_INDEX The \a index does not exist.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see FindFlat(const char*, BFlattenable*) const

        \since BeOS R3
*/


//! @}


/*!
        \name Replacing Data

        Look at ReplaceData() for a general introduction to replacing data.
*/


//! @{


/*!
        \fn status_t BMessage::ReplaceData(const char* name, type_code type,
                const void* data, ssize_t numBytes)
        \brief Replace the data at label \a name.

        This method is an overloaded method that replaces the data at
        \a index \c 0. See
        ReplaceData(const char*, type_code, int32, const void*, ssize_t).

        \param name The name associated with the data to replace.
        \param type The type of the data.
        \param data A pointer to the new data that needs to be copied into
               the message.
        \param numBytes The size of the new data.

        \returns A status code, \c B_OK on success or an error code.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceData(const char* name, type_code type,
                int32 index, const void* data, ssize_t numBytes)
        \brief Replace the data at label \a name at a specified
               \a index.

        The conditions for replacing data are that the\a name is correct,
        the \a type matches and the data entry at \a index exists.

        There is also a collection of convenience methods, that allow you to
        efficiently replace rectanges (ReplaceRect()), booleans (ReplaceBool()),
        and so on.

        \param name The name associated with the data to replace.
        \param type The type of the data.
        \param index The index in the array to replace.
        \param data A pointer to the new data that needs to be copied into
               the message.
        \param numBytes The size of the new data.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_VALUE One of the input parameters are invalid. Check that
                you did not pass \c NULL, and in case the field has fixed sized
                data, check that \a numBytes is the same as the specified fixed
                size.
        \retval B_BAD_INDEX The \a index is out of range.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceRect(const char* name, BRect aRect)
        \brief Replace a rectangle at the label \a name.

        This method is an overloaded method of
        ReplaceRect(const char*, int32, BRect).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aRect The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceRect(const char* name, int32 index,
                BRect aRect)
        \brief Replace a rectangle at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_RECT_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aRect The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceRect(const char*, BRect)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplacePoint(const char* name, BPoint aPoint)
        \brief Replace a point at the label \a name.

        This method is an overloaded method of
        ReplacePoint(const char*, int32, BPoint).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aPoint The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The object now contains the requested data.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplacePoint(const char* name, int32 index,
                BPoint aPoint)
        \brief Replace a point at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_POINT_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aPoint The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplacePoint(const char*, aPoint)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceString(const char* name, const char* aString)
        \brief Replace a string at the label \a name.

        This method is an overloaded method of
        ReplaceString(const char*, int32, const char*).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aString The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceString(const char* name, int32 index,
                const char* aString)
        \brief Replace a string at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be
        replaced, if it matches the \c B_STRING_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aString The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceString(const char*, const char*)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceString(const char* name,
                const BString& aString)
        \brief Replace a string at the label \a name.

        This method is an overloaded method of
        ReplaceString(const char*, int32, BString&).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aString The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R5
*/


/*!
        \fn status_t BMessage::ReplaceString(const char* name, int32 index,
                const BString& aString)
        \brief Replace a string at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_STRING_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aString The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceString(const char*, BString&)

        \since BeOS R5
*/


/*!
        \fn status_t BMessage::ReplaceInt8(const char* name, int8 value)
        \brief Replace an integer at the label \a name.

        This method is an overloaded method of
        ReplaceInt8(const char*, int32, int8).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param value Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceInt8(const char* name, int32 index,
                int8 value)
        \brief Replace an integer at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_INT8_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param value Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceInt8(const char*, int8)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceInt16(const char* name, int16 value)
        \brief Replace an integer at the label \a name.

        This method is an overloaded method of
        ReplaceInt16(const char*, int32, int16).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param value Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceInt16(const char* name, int32 index,
                int16 value)
        \brief Replace an integer at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_INT16_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param value Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceInt16(const char*, int16)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceInt32(const char* name, int32 value)
        \brief Replace an integer at the label \a name.

        This method is an overloaded method of
        ReplaceInt8(const char*, int32, int32).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param value Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceInt32(const char* name, int32 index,
                int32 value)
        \brief Replace an integer at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_INT32_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param value The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceInt32(const char*, int32)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceInt64(const char* name, int64 value)
        \brief Replace an integer at the label \a name.

        This method is an overloaded method of
        ReplaceInt8(const char*, int32, int64).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param value Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceInt64(const char* name, int32 index,
                int64 value)
        \brief Replace an integer at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_INT64_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param value The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceInt64(const char*, int64)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceBool(const char* name, bool aBoolean)
        \brief Replace a boolean at the label \a name.

        This method is an overloaded method of
        ReplaceBool(const char*, int32, bool).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aBoolean Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceBool(const char* name, int32 index,
                bool aBoolean)
        \brief Replace a boolean at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_BOOL_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aBoolean Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceBool(const char*, bool)

        \since BeOS R5
*/


/*!
        \fn status_t BMessage::ReplaceFloat(const char* name, float aFloat)
        \brief Replace a float at the label \a name.

        This method is an overloaded method of
        ReplaceFloat(const char*, int32, float).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aFloat The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceFloat(const char* name, int32 index,
                float aFloat)
        \brief Replace a float at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_FLOAT_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aFloat The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceFloat(const char*, float)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceDouble(const char* name, double aDouble)
        \brief Replace a double at the label \a name.

        This method is an overloaded method of
        ReplaceDouble(const char*, int32, double).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aDouble Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceDouble(const char* name, int32 index,
                double aDouble)
        \brief Replace a double at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_DOUBLE_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aDouble Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceDouble(const char*, double)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceColor(const char* name, rgb_color aColor)
        \brief Replace a color at the label \a name.

        This method is an overloaded method of
        ReplaceColor(const char*, int32, rgb_color).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param aColor Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since Haiku R1
*/


/*!
        \fn status_t BMessage::ReplaceColor(const char* name, int32 index,
                rgb_color aColor)
        \brief Replace a rgb_color at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_RGB_32_BIT_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param aColor Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceColor(const char*, rgb_color)

        \since Haiku R1
*/


/*!
        \fn status_t BMessage::ReplacePointer(const char* name,
                const void* pointer)
        \brief Replace a pointer at the label \a name.

        This method is an overloaded method of
        ReplacePointer(const char*, int32, const void*).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param pointer Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplacePointer(const char* name, int32 index,
                const void* pointer)
        \brief Replace a pointer at the label \a name at a specified \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_POINTER_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param pointer Where to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplacePointer(const char*, const void*)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceMessenger(const char* name,
                BMessenger messenger)
        \brief Replace a messenger at the label \a name.

        This method is an overloaded method of
        ReplaceMessenger(const char*, int32, BMessenger).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param messenger The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceMessenger(const char* name, int32 index,
                BMessenger messenger)
        \brief Replace a messenger at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_MESSENGER_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param messenger The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceMessenger(const char*, BMessenger)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceRef(const char* name, const entry_ref* ref)
        \brief Replace a reference to a file at the label \a name.

        This method is an overloaded method of
        ReplaceRef(const char*, int32, entry_ref*).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param ref The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceRef(const char* name, int32 index,
                const entry_ref* ref)
        \brief Replace a reference to a file at the label \a name at a
                specified \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_REF_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param ref The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceRef(const char*, entry_ref*)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceMessage(const char* name,
                const BMessage* message)
        \brief Replace a message at the label \a name.

        This method is an overloaded method of
        ReplaceMessage(const char*, int32, BMessage*).
        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param message The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceMessage(const char* name, int32 index,
                const BMessage* message)
        \brief Replace a message at the label \a name at a specified
               \a index.

        The data at the specified \a name and \a index will be replaced, if it
        matches the \c B_MESSAGE_TYPE.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param message The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceMessage(const char*, BMessage*)

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceFlat(const char* name, BFlattenable* object)
        \brief Replace a flattened object at the label \a name.

        This method is an overloaded method of
        ReplaceFlat(const char*, int32, BFlattenable*).

        It replaces the data at \a index \c 0.

        \param name The name associated with the data to replace.
        \param object The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \since BeOS R3
*/


/*!
        \fn status_t BMessage::ReplaceFlat(const char* name, int32 index,
                BFlattenable* object)
        \brief Replace a flattened object at the label \a name at a
               specified \a index.

        The data at the specified \a name and \a index will be
        replaced, if it matches the type returned by your object. This method uses
        BFlattenable::TypeCode() to determine the type of the object.

        \param name The name associated with the data to replace.
        \param index The index in the array to replace.
        \param object The object to store in the message.

        \returns A status code, \c B_OK on success or an error code.
        \retval B_OK The operation succeeded.
        \retval B_BAD_INDEX The index was out of range.
        \retval B_NAME_NOT_FOUND There is no field with this \a name.

        \see ReplaceFlat(const char*, BFlattenable*)

        \since BeOS R3
*/


//! @}


/*!
        \name Operators

        The new and delete operators are deprecated and are only provided for
        backwards compatibility.
*/


//! @{


/*!
        \fn BMessage& BMessage::operator=(const BMessage& other)
        \brief Copy one message into another.

        See the copy constructor, BMessage(const BMessage& other), for details on
        what is copied, and what isn't.

        \since BeOS R3
*/


/*!
        \fn void* BMessage::operator new(size_t size)
        \brief Allocates \a size bytes of memory for a BMessage.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn void* BMessage::operator new(size_t, void* pointer)
        \brief Allocates \a size bytes of memory for a BMessage.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn void BMessage::operator delete(void* pointer, size_t size)
        \brief Frees memory allocated by new.

        \warning This method is deprecated, do not use.

        \since BeOS R5
*/


//! @}


/*!
        \name Deprecated Methods

        These methods are likely to disappear as they have been replaced by safer
        and more powerful methods but are implemented for the purpose of binary
        compatibility.
*/


//! @{


/*!
        \fn bool BMessage::HasRect(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasPoint(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasString(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasInt8(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasInt16(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasInt32(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasInt64(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasBool(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasFloat(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasDouble(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasPointer(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasMessenger(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasRef(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasMessage(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasFlat(const char*, const BFlattenable*) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasFlat(const char*, int32, const BFlattenable*) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::HasData(const char*, type_code, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn BRect BMessage::FindRect(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn BPoint BMessage::FindPoint(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn const char* BMessage::FindString(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn int8 BMessage::FindInt8(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn int16 BMessage::FindInt16(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn int32 BMessage::FindInt32(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn int64 BMessage::FindInt64(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn bool BMessage::FindBool(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn float BMessage::FindFloat(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


/*!
        \fn double BMessage::FindDouble(const char*, int32) const
        \brief Deprecated.

        \warning This method is deprecated, do not use.

        \since BeOS R3
*/


//! @}


/*!
        \name Finding Data Convenience Methods

        These methods may be used as alternatives to the Find data methods above
        which allow you to specify a default value to use if the value you are
        looking for is not found and return the result instead of filling out an
        out parameter and status code. If you are not interested in the status code
        these methods allow for some code simplification.

        For example, instead of writing:

\code
bool enabled;
if (FindBool("enabled", &enabled) != B_OK)
        enabled = false;
\endcode

        you can write the following:

\code
bool enabled = GetBool("enabled", false);
\endcode

        reducing the example to a single line.
*/


//! @{


/*!
        \fn bool BMessage::GetBool(const char* name, bool defaultValue) const
        \brief Return the boolean value from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn bool BMessage::GetBool(const char* name, int32 index,
                bool defaultValue) const
        \brief Return the boolean value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int8 BMessage::GetInt8(const char* name, int8 defaultValue) const
        \brief Return the int8 value from message with \a name, or \a defaultValue
               if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int8 BMessage::GetInt8(const char* name, int32 index,
                int8 defaultValue) const
        \brief Return the int8 value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint8 BMessage::GetUInt8(const char* name, uint8 defaultValue) const
        \brief Return the uint8 value from message with \a name, or \a defaultValue
               if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint8 BMessage::GetUInt8(const char* name, int32 index,
                uint8 defaultValue) const
        \brief Return the uint8 message from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int16 BMessage::GetInt16(const char* name, int16 defaultValue) const
        \brief Return the int16 value from message with \a name, or \a defaultValue
               if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int16 BMessage::GetInt16(const char* name, int32 index,
                int16 defaultValue) const
        \brief Return the int16 value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint16 BMessage::GetUInt16(const char* name, uint16 defaultValue) const
        \brief Return the uint16 value from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint16 BMessage::GetUInt16(const char* name, int32 index,
                uint16 defaultValue) const
        \brief Return the uint16 value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int32 BMessage::GetInt32(const char* name, int32 defaultValue) const
        \brief Return the int32 value from message with \a name, or \a defaultValue
               if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int32 BMessage::GetInt32(const char* name, int32 index,
                int32 defaultValue) const
        \brief Return the int32 value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint32 BMessage::GetUInt32(const char* name, uint32 defaultValue) const
        \brief Return the uint32 value from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint32 BMessage::GetUInt32(const char* name, int32 index,
                uint32 defaultValue) const
        \brief Return the uint32 value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int64 BMessage::GetInt64(const char* name, int64 defaultValue) const
        \brief Return the int64 value from message with \a name, or \a defaultValue
               if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn int64 BMessage::GetInt64(const char* name, int32 index,
                int64 defaultValue) const
        \brief Return the int64 value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint64 BMessage::GetUInt64(const char* name, uint64 defaultValue) const
        \brief Return the uint64 value from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn uint64 BMessage::GetUInt64(const char* name, int32 index,
                uint64 defaultValue) const
        \brief Return the uint64 value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn float BMessage::GetFloat(const char* name, float defaultValue) const
        \brief Return the float value from message with \a name, or \a defaultValue
               if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn float BMessage::GetFloat(const char* name, int32 index,
                float defaultValue) const
        \brief Return the float value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn double BMessage::GetDouble(const char* name, double defaultValue) const
        \brief Return the double value from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn double BMessage::GetDouble(const char* name, int32 index,
                double defaultValue) const
        \brief Return the double value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn rgb_color BMessage::GetColor(const char* name, rgb_color defaultValue) const
        \brief Return the rgb_color value from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn rgb_color BMessage::GetColor(const char* name, int32 index,
                rgb_color defaultValue) const
        \brief Return the rgb_color value from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn const char* BMessage::GetString(const char* name,
                const char* defaultValue) const
        \brief Return the string from message with \a name, or \a defaultValue if
               not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn const char* BMessage::GetString(const char* name, int32 index,
                const char* defaultValue) const
        \brief Return the string from message with \a name and \a index, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BAlignment BMessage::GetAlignment(const char* name,
                const BAlignment& defaultValue) const
        \brief Return the BAlignment object from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BAlignment BMessage::GetAlignment(const char* name, int32 index,
                const BAlignment& defaultValue) const
        \brief Return the BAlignment object from message with \a name and \a index,
               or \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BRect BMessage::GetRect(const char* name, const BRect& defaultValue) const
        \brief Return the BRect object from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BRect BMessage::GetRect(const char* name, int32 index,
                const BRect& defaultValue) const
        \brief Return the BRect object from message with \a name and \a index,
               or \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BPoint BMessage::GetPoint(const char* name,
                const BPoint& defaultValue) const
        \brief Return the BPoint object from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BPoint BMessage::GetPoint(const char* name, int32 index,
                const BPoint& defaultValue) const
        \brief Return the BPoint object from message with \a name and \a index,
               or \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BSize BMessage::GetSize(const char* name,
                const BSize& defaultValue) const
        \brief Return the BSize object from message with \a name, or
               \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


/*!
        \fn BSize BMessage::GetSize(const char* name, int32 index,
                const BSize& defaultValue) const
        \brief Return the BSize object from message with \a name and \a index,
               or \a defaultValue if not found.

        \param name The name of the item to retrieve.
        \param index The index of the item to retrieve if there is more than one.
        \param defaultValue The value to use if the item specified by \a name
               is not found.

        \return The item with \a name, or \a defaultValue if not found.

        \since Haiku R1
*/


//! @}