C++ :: Extended Initializer Lists Flag On Class Constructor

I just got this warning from codeblocks:

Code: extended initializer lists only available with -std=c++11 or -std=gnu++11 that I belive is due to having initialized a class array in the constructor somewhat like this:
Code: class xpto {
public;
xpto():num{25,25}{}
int num[2];
};

Since the code I'm developing is not meant to be compiled only by me and I want to ensure there are no incompatibilities with other machines I would like to kow whats the best way to initialize the array that is not c++11 dependent.

Is there no way to do it directly on the constructor "pre-instructions" (don't know the correct designation for the initialization section)? or do I have to put the instructions on the constructor body.