title: How to enable C++11 in CLion?
body: <p>I'm trying to run C++11 code in CLion but it doesn't work. It says:</p>
  
  <pre><code>...
      /projects/CLion/untitled/main.cpp:7:1: note: C++11 ‘constexpr’ only available with -std=c++11 or -std=gnu++11
  ...
  </code></pre>
  
  <p>I tried to set <code>CMAKE_C_FLAGS</code> to <code>-std=c++11</code> or <code>-std=gnu++11</code> but I still have the same problem. Regular C++ code compiles fine.</p>
  
  <p>What flag do I have to set in CLion's CMake window to compile my C++11 code?</p>