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<concept xml:lang="en" id="GUID-E3210353-EEC2-56CB-AD75-309E5DCDEDD1"><title>The read stream interface</title><prolog><metadata><keywords/></metadata></prolog><conbody><p><codeph>RReadStream</codeph> is an abstract class that presents the necessary interface for internalising from a stream. When called, the <codeph>InternalizeL()</codeph> member function of a class is passed a reference to a concrete read stream object; for example, an object constructed from a class such as <codeph>RStoreReadStream</codeph>. This allows <codeph>InternalizeL()</codeph> to read the object's data from any stream, regardless of that stream’s concrete implementation.</p> <p>All data types, including non-class types, can be internalised, although some can only be internalised using the templated stream <codeph>operator&gt;&gt;</codeph>.</p> <p><codeph>RReadStream</codeph> provides support for internalising:</p> <ul><li id="GUID-65D06736-B345-5734-AD5C-A3F48B533863"><p><codeph>TInt</codeph>, <codeph>TUint</codeph>, <codeph>TReal</codeph> and <codeph>TReal64</codeph> types.</p> </li> <li id="GUID-15EEE372-8BEE-5759-9C26-FB3024196099"><p>The content of a descriptor.</p> </li> </ul> <p>It also provides support for <i>externalising</i> data to a write stream.</p> <p>The <codeph>ReadInt8L()</codeph>, <codeph>ReadUint8L()</codeph>, <codeph>ReadInt16L()</codeph> and <codeph>ReadUint16L()</codeph> member functions allow applications to extract data from the stream written as 8 bit and 16 bit values.</p> <p>The read stream interface also allows data to be internalised to a location defined by a pointer and a length. However, this functionality is rarely used by application code.</p> <section><title>See also</title> <p><xref href="GUID-D7211372-9411-5A18-88F0-615F4983A2E0.dita">Store streams</xref> </p> </section> </conbody></concept>