A first solution is to create a constructor for your structure (as a struct is a class, you can do it as for any other class). Then put a break point into it and check if the constructor is called before your first call to the function someFunction.

The initialisation at the start of the program can sometimes be in an unexpected order that will give you unexpected results.

Just imagine that you call this function in the constructor of your application object. This one is a global variable as well and its contructor might be called before your array is constructed.