In which real situations have you seen C++ usage for web applications wth PHP?

I've looked throught the forum, I've asked uncle Google and I know that:
- PHP extensions can be written in C/C++
- there is a great amount of C/C++ libraries you can use in PHP projects
- C/C++ has a great efficiency (if you use if well)
- you can process a great amount of data with C/C++, write crawlers
- there is even FastCGI, Wt, CppCMS, etc...

But what's more? Maybe some specific server-side tasks? Can you list them?

I'm used to write in PHP but at University I have a long C++ course. Learning only for passing would be a shame.

I'll be grateful for help.

c++ is used for a great deal more than web development. Most PC games and desktop apps are written in c++. c++ can also be used as CGI programs (google "CGI programming")

Thanks for answers! Can you list more for web programming?

I only used it once -- to generate an HTML page from the results of SQL queries. Don't know why they wanted me to use c++ for that instead of PHP. I was on a team of about 100 programmers, some c, some web. I'm not a web programmer so I can't explain it. AFAIK PHP can access SQL, sometimes easier than c++.

Maybe some specific server-side tasks?

You can use it to write UDF's for MySQL.