Pretty much on performance concerns. I know that there's at least going to be one copy performed while doing the compression, from uncompressed to compressed. Here's how I do it:

filtering_ostream *fos = new filtering_ostream();

fos->push(bzip2_compressor());

string *x = acquireStringFromPool();   //This is just a blocking pointer return that reaches into a list of string *, each that are allocated with new string(30000,0); (it's multithreaded, ok lol :) )

fos->push(boost::iostreams::back_insert_device<string>(x));   //This is what I was searching for all along.

then later, when I want to write to fos I do,

*fos << *doc;    //I go straight from container to compression.

Maybe my specifications that "I don't want to find that it's copying at all" were a bit weird, because obviously it has to move the data right? I'm just saying that most of the examples I would see would be something like

compress(string x) {

   stringstream ss(x);  //unnecessary initialization in my case, couldn't find an example without this

   //something similar to what I did...

}

On Tue, Jan 14, 2014 at 10:08 AM, Krzysztof Czainski <1czajnik@gmail.com> wrote:

2014/1/14 Kenneth Adam Miller <kennethadammiller@gmail.com>

I figured out how to do it:

filtering_ostream fos;

fos.push(back_insert_device<string>(x));

[...] 

On Tue, Jan 14, 2014 at 8:20 AM, Kenneth Adam Miller <kennethadammiller@gmail.com> wrote:

I have an object for which operator << is defined, myobj.

I want to compress into a buffer, and I know that this can be done with boost. I would prefer a buffer that dynamically resizes, but that only allocates new space, preferably treating discontiguous space brought on by new allocations as though the whole buffer was one piece; I don't want to find that it's copying data at all. So vector won't work as a buffer; there's no need for it to be contiguous, just as fast as possible.

Hi,

Did you satisfy your "no copying" requirement? How? 

Was the requirement based only on performance concerns?

Regards,

Kris

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