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<TITLE>User-Defined Character Types</TITLE>
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<A HREF="41.html"><IMG SRC="images/bprev.gif" WIDTH=20 HEIGHT=21 ALT="Previous file" BORDER=O></A><A HREF="noframes.html"><IMG SRC="images/btop.gif" WIDTH=56 HEIGHT=21 ALT="Top of Document" BORDER=O></A><A HREF="booktoc.html"><IMG SRC="images/btoc.gif" WIDTH=56 HEIGHT=21 ALT="Contents" BORDER=O></A><A HREF="tindex.html"><IMG SRC="images/bindex.gif" WIDTH=56 HEIGHT=21 ALT="Index page" BORDER=O></A><A HREF="41-2.html"><IMG SRC="images/bnext.gif" WIDTH=25 HEIGHT=21 ALT="Next file" BORDER=O></A><DIV CLASS="DOCUMENTNAME"><B>Apache C++ Standard Library User's Guide</B></DIV>
<H2>41.1 User-Defined Character Types</H2>
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<P>One of the fundamental differences between the new, templated iostreams and the traditional iostreams is the ability of the new iostreams to accommodate user-defined character types. It's now possible to use the C++ iostreams interface with arbitrary character-like types, as well as with ordinary <SAMP>char</SAMP>s. </P>
<P>Of course, this flexibility comes at a price. Any user-defined character type must satisfy certain requirements. The type really must act like an ordinary <SAMP>char</SAMP> in most circumstances. In addition, several classes must be defined to support the type in the iostreams environment.</P>
<A NAME="4111"><H3>41.1.1 Requirements for User-Defined Character Types</H3></A>
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<P>In general, user-defined character types must meet the requirements of a POD type:</P>

<UL><PRE>
struct Echar
{
  char c;
  char i;
};

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