c++ in atmel studio 6

i'm using atmel studio 6. I've opened a example project (Basic FreeRTOS) that i have adapted for the due.
Everything works fine...compiling and debugging.

Now i'm adding some cpp and H file for a humidity sensor. The h file includes a class definition:

class sensor
int read_sensor(int pin);
int humidity;
int temperature;

my problem is that class is not recognised: unknown type name 'class'
Anyone had this problem? As far as i know, the projects in AS6 are C/C++. Should i do something to force C++?

I'm doing something similar and I have the exact same problem.

I couldn't yet fix it. However, when I install Arduino Template Express, everything works fine.

Without it though, somehow the AVR Studio treats .h files as .c I guess...