.cpp file ends up being highlighted by the generic highlighter

I did the following:

1. File->New File or project
2. Select General, Text File
3. Click on "Choose..." button
4. Provide file name "test.cpp"
5. Click on "Next"
6. Click on "Finished"

Result:
A .cpp file which is highlighted by the generic highlighter, code completion does not work

Expected Result:
The .cpp files is opened in the C++ text editor, highlighting, semantic checking and code completion is available.

Additional information:
I should probably just have used the proper wizard to create a C++ source file. I assumed that would add a copyright header and I did not wan that.