ciated; otherwise, they throw <CODE>std::ios_base::failure</CODE>.  The <CODE>T</CODE> constructors involved must take all arguments by value or <CODE>const</CODE> reference. 
</P>
<P>
    It is not possible to specify a custom buffer size or putback buffer size using these members.
</P>

<A NAME="stream_is_open"></A>
<H4><CODE>stream::is_open</CODE></H4>
<PRE>    <SPAN CLASS="keyword">bool</SPAN> <B>is_open</B>() <SPAN CLASS="keyword">const</SPAN>;</PRE>
    
<P>Returns true if there is an instance of the 