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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-9452D60C-CD3E-570D-885F-F329264AB6F4" xml:lang="en"><title>The

    13 array buffer</title><shortdesc>Describes the array buffer.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>All arrays have an array buffer. The implementation of this buffer and

    15 the way it is used depend on the specific type of array.</p>

    16 <p>In fixed length arrays and packed arrays the elements are contained within

    17 the array buffer itself.</p>

    18 <p>In variable length arrays each element is contained within its own heap

    19 cell and the array buffer contains <i>pointers</i> to the elements.</p>

    20 <p>Logically, an array buffer is linear but, physically, it can be organised

    21 either as a flat buffer or a segmented buffer.</p>

    22 <p>In general, you can choose between array classes which use a flat array

    23 buffer and array classes which use a segmented array buffer. The choice depends

    24 on how the array is to be used.</p>

    25 <p>A segmented array buffer is implemented using a <codeph>CBufSeg</codeph> object.</p>

    26 <p>A flat array buffer is implemented either:</p>

    27 <ul>

    28 <li id="GUID-F3E43492-AE56-5290-863D-15ED57DFCC6F"><p>directly by the array

    29 as a piece of linear memory.</p> </li>

    30 </ul>

    31 <p>or</p>

    32 <ul>

    33 <li id="GUID-B7472961-5E2C-5ECA-864C-7B1FD547FD5F"><p>using a <codeph>CBufFlat</codeph> object.</p> </li>

    34 </ul>

    35 <p>The first has a simple and efficient implementation but has some restrictions

    36 on the size of an array element and is limited to holding fixed length elements.

    37 The second is a more general implementation but is only limited by the memory

    38 available.</p>

    39 <section id="GUID-72E6EC4A-DE51-44A9-A83D-16C3E33874E1"><title>See also</title> <p><xref href="GUID-112AAFA5-B4C9-5B62-A106-FB5097C13A0E.dita">Using

    40 Dynamic Buffers</xref> </p> </section>

    41 </conbody></concept>