How to use PROGMEM in a .h/.cpp file instead of a .ino file?

Question

I want to use a lot of .h/.cpp files to be used by my ino sketch. In one of these .cpp files (and later more) I want to use constant arrays (like lookup tables). To save SRAM I want to use PROGMEM.

What worked before in the Ino sketch is:

const uint8_t _red[]   PROGMEM = { 0, 9, 10, 220, 230, 240, 255 };

But when I put the line above in a .h or .cpp file I get the error:

Par.h:13:25: error: expected initializer before 'PROGMEM'

Should I include something or can't I use PROGMEM in a .h/.cpp file?

Answer 1

I already found the answer.

Include:

#include <avr/pgmspace.h>

Update

See also remark of AnT, which is a more generic (and in most cases better solution):

#include "Arduino.h"

(just to help others with the same problem).