One area in C++ I had never really spent a lot of time with until early last year is the iostreams library. I thought I understood it pretty well. At a superficial level, it made perfect sense: replace printf/scanf with an abstract interface for serialization that objects could implement for themselves.
As a developer whose post-stdio-era coding usually targeted things like graph databases instead of text files, I didn't have all that many occasions to use iostreams. But as I became more involved in exchanging small conceptual programs with other developers, I realized that they are the "lingua franca" of standard C++. Using them began to teach me that there were many things about them I didn't know...and that they could be very useful, as well as very tricky.
For instance, do you know the difference between these two lines?
std::cout << std::endl;
/* vs... */
std::cout << '\n';
I didn't! That's just for starters, so I gave a presentation on the topic to my Austin C/C++ Group
in October 2011. In it, I represent some of my new understandings:
At first, I delayed on publishing it to the Web for fear that it may not be 100% right. But then it languished in a private Google Docs presentation for a year and a half. I found it today, and if I'm worried about its inaccuracy it's sure not going to get any better by leaving it there. And it might help someone, as I know there are a large number of people on the Internet who are even more less than 100% right. :-P
So here it is, and corrections are of course welcome--just leave a comment!
Learning the details about this would not have happened without the help of the active C++ community on SO. That's where I spent most of my recreational programming time--instead of writing blog entries--in 2011. Both asking and answering questions offers insights. While some people seem to have a bit of what amounts to an "online game addiction", it's a case where their affliction can benefit you and the common good. :P