How do I enable C++14 in the ClangCodeModel (or even the "normal" one)?

I added `CONFIG += c++14` in the `.pro` file and the project compiles fine with both `gcc` and `clang` but the IDE is annyoing me with spurious warnings on C++14 constructs.

When looking at the "C++ Code Model Inspector", the "Project Parts->General" tab says 

> 
> Language Version CXX11
> 
> 
> 

despite the config entry. It seems the IDE's CodeModel does not pick that up.