Come on, if we are having this conversation and you've already taken the pains to add a contrary comment - I was fully expecting you will elaborate on those use cases :) Are you thinking embedded web servers may be? What else?
but yup, low memory/cpu/ram situations are one clear place where a c++ web app makes a heap of sense.
Also things like routers, where there is an environment that doesn't change frequently (..or often at all for years..).
There is also a bunch of use cases where the fact that installing/replacing/updating the web app is as simple as replacing a single binary is a real win.
There just are a bunch of places where it makes perfect sense to use a c++ web app, and none at all to use frameworks like RoR.
Its not a big deal, there are entire worlds of requirements and use cases that look and sound nothing like 'public facing web application', where the ability to provide an HTML interface is a win, and the ability to lower resource requirements from something like RoR is a win.
The only reason I posted is that it just makes me sad when people are so utterly oblivious to the worlds that they dont know, and - because of that - are tracked into making definitive statements about things, when they should probably preface their comments with "to my knowledge..." or "Im not aware of" or even preface it with a genuine question "why is something like this useful?, I dont understand.."
There is nothing wrong with admitting you do not understand something and asking for clarification :)
To be frank, that's not something I don't understand. It's just a resource constrained environment use case that anyone can understand. What I don't understand is how common those use cases are today given my home router runs with 32Mb RAM and can use PHP instead of C++, never mind the fact that it doesn't need a full fledged C++ Web Framework to begin with!
For some definition of the word, I believe that Facebook is effectively deploying a c++ web app as part of its solution at this point.
There are many use cases for which RoR or PHP is the better solution, but it turns out it is imply true that there are others for which a c++ web app is the better solution.
Go figure :)
I thought Facebook mostly used C++ for their PHP VM? Facebook itself is alot of PHP, they also use Cassandra (Java DB) for inbox messages I believe.
Didn't know they switched to HBase, it's still Java though.
"Facebook uses hphpi (and now hhvm) for day-to-day software development, but uses the HipHop compiler (hphpc) to create optimized binaries that serve the Facebook website. hphpc is in essence a traditional static compiler that converts PHP→AST→C++→x64."
According to wikipedia: http://en.wikipedia.org/wiki/HipHop_for_PHP
"in Q1 2013, the production version of facebook.com started running on HHVM, replacing HPHPc."
I wonder how well silverstripe runs on it....