EDIT: It turns out this really isn't specific to Eclipse Kepler. I had to use the same process for Eclipse Juno. The problem was that there seem to be missing steps in other posts answering this same question.
I'm using Eclipse Kepler for C++ and I'm trying to use C++11 and getting errors. When I compile I get the error
error: range-based-for loops are not allowed in C++98 mode
I've followed the instructions from the post
Eclipse CDT C++11/C++0x support
and the solution given for Eclipse Juno isn't working.
Different comments have suggested restarting eclipse and cleaning and rebuilding. That hasn't made a difference.
There's two things you have to do, first you need to setup your compiler, then you need to setup CDT's language processor. Since you didn't mention which compiler you're using, I'll assume it's GCC but the steps will be similar for other compilers. (Note that you need a compiler that supports C++11, of course.)
Setting up the compiler is fairly straightforward:
At this point you should be able to rebuild your project and get it to run. But CDT still may show errors for C++11 includes. Here's how you can resolve that: