What happens if I define a 0-size array in C/C++?

Question

Just curious, what actually happens if I define a zero-length array int array[0]; in code? GCC doesn\'t complain at all.

Sample Program

Answer 1

I'll add that there is a whole page of the online documentation of gcc on this argument.

Some quotes:

Zero-length arrays are allowed in GNU C.

In ISO C90, you would have to give contents a length of 1

and

GCC versions before 3.0 allowed zero-length arrays to be statically initialized, as if they were flexible arrays. In addition to those cases that were useful, it also allowed initializations in situations that would corrupt later data

so you could

int arr[0] = { 1 };

and boom :-)