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<concept id="GUID-4F882837-0DA1-5243-BA7B-696B418A160E" xml:lang="en"><title>How to

use a package buffer</title><shortdesc>Explains how to use <codeph>TPckg&lt; &gt;</codeph>.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>The following code fragments show an object or a C type struct being written

to a file:</p>

<codeblock id="GUID-852DE4D2-DF5B-50BD-B347-627809FBFA22" xml:space="preserve">TXxx x;                    // some structure

TPtr8 xDes(&x, sizeof(x)); // descriptor of that structure

file.Write(xDes);          // write structure to file</codeblock>

<p>While this approach works, it is not type safe. The descriptor could be

mistaken as referring to an object which is not of type <codeph>TXxx</codeph>.</p>

<p>Use a package buffer which works in a similar way but enforces type safety,

as the following code fragment shows:</p>

<codeblock id="GUID-7EBF5473-C9C8-5056-AEFA-6B3CC8822765" xml:space="preserve">TXxx x;                    // some structure

TPckg<TXxx> xDes(x);       // make into a package

file.Write(xDes);          // now write structure t file</codeblock>