Re: [Boost-users] Read/write with gzip

On 4/27/2011 11:05 AM, Anders Knudby wrote:

On Wed, Apr 27, 2011 at 12:27 PM, Ted Byers mailto:r.ted.byers@gmail.com> wrote:

On Tue, Apr 26, 2011 at 8:54 PM, Anders Knudby mailto:knudby@gmail.com> wrote:

Is there a reason not to invoke the stream's member function 'close' at this point? You are, after all, reopening the same file later in your program.

Cheers

Ted

Thanks for the help. The problem of writing the file and then trying to read it later in the same process is an artefact of my example, in reality I have one program to write the files, and another to read them again. But the reason I'm not specifically closing the filtering_stream is that I don't know how! I thought I could treat it as a normal iostream (e.g. using read, write etc.), but the normal closing of an iostream - in.close() - doesn't compile. Instead it gives me the following error: "error C2039: 'close' : is not a member of 'boost::iostreams::filtering_stream<Mode>". I have found a mention somewhere that I need to make the filtering_stream 'closeable', but I haven't found out how to do that. Any help would be appreciated, I do like to close my streams...

In the meantime, I have somehow managed to get my code to work. I'm not sure how, but it is definitely related to the closing or not of the filtering_stream. If someone has a simple example of how to create and then close/destroy a filtering_streambuf that would be great. I can't find a single example in the Boost documentation, but maybe I'm just not looking in the right place or sufficiently code-literate.

I believe I've used reset(). The following thread has some useful responses in it (especially from the original author Jonathon Turkanis) that explains some of the issues around flushing): http://boost.2283326.n4.nabble.com/gzip-compressor-cannot-be-flushed-and-clo...