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unnamed-faq-63
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     To: jimmey@lexis-nexis.com (Jimmey Todd)
     Subject: Re: FLEX question regarding istream vs ifstream
     In-reply-to: Your message of Mon, 08 Dec 1997 15:54:15 PST.
     Date: Mon, 15 Dec 1997 13:21:35 PST
     From: Vern Paxson <vern>
     
     >         stdin_handle = YY_CURRENT_BUFFER;
     >         ifstream fin( "aFile" );
     >         yy_switch_to_buffer( yy_create_buffer( fin, YY_BUF_SIZE ) );
     >
     > What I'm wanting to do, is pass the contents of a file thru one set
     > of rules and then pass stdin thru another set... It works great if, I
     > don't use the C++ classes. But since everything else that I'm doing is
     > in C++, I thought I'd be consistent.
     >
     > The problem is that 'yy_create_buffer' is expecting an istream* as it's
     > first argument (as stated in the man page). However, fin is a ifstream
     > object. Any ideas on what I might be doing wrong? Any help would be
     > appreciated. Thanks!!
     
     You need to pass &fin, to turn it into an ifstream* instead of an ifstream.
     Then its type will be compatible with the expected istream*, because ifstream
     is derived from istream.
     
     		Vern