Re: [boost] [bitstream] Copy stream buffer or pass pointer?

Subject: Re: [boost] [bitstream] Copy stream buffer or pass pointer?
From: Daryle Walker (darylew_at_[hidden])
Date: 2013-07-17 23:21:10

> Date: Wed, 17 Jul 2013 22:09:08 -0500
> From: plong_at_[hidden]
> 
> For example, the following snippet prints 
> "hello, goodbye".
> 
> char c[BUFSIZ] = "hello";
> istringstream iss(c);
> strcpy(c, "goodbye");
> cout << iss.str() << ", " << c;
> 
> However, the library I'm working on doesn't copy. Instead, pointers are 
> passed in and out. So, for example, this code prints "goodbye, goodbye".
> 
> char c[BUFSIZ] = "hello";
> ibitstream ibs(c);
> strcpy(c, "goodbye");
> cout << ibs.data() << ", " << c;
> 
> I don't think either way is more correct than the other. The reason I 
> don't copy is for memory and CPU performance, thinking that the streams 
> a bit-stream library typically processes are larger than the streams 
> that a string-stream library processes and are more time critical. I 
> very well may be mistaken, though. Anyway, what do you people think? 
> Copy or don't copy? Maybe I should do copies just to follow the 
> semantics of std::stringstream.

I would suggest copying.  Here you have two sources; what happens with three?  The reference method doesn't scale.  By-reference also has lifetime issues.
 
Daryle W.