Originally Posted by garysk

As I pointed out in my reply to @jimmacnamara, there was no overflow. By means of logic that is not obvious to me, the compiler made certain decisions, which resulted in two things:

1. The data aligned, one comma-separated datum per named member of each instance of the structure within the array of structures. The values expected, except for the NULL-initialized char [5], appeared in their expected places in the array and within every element of the array. If they didn't align one to one, that would have been the time to break out the additional curly braces.

2. The "NULL" initializer of the member array was interpreted as a signal to initialize the member array with null bytes. Somehow, no doubt through application of fundamental rules of the language (which is what is not clear to me), the compiler made the decision to convert the *((void *)0) to (char)0, essentially converting a declared pointer into a declared integer.

To my knowledge there is not a simpler explanation of the decision (the need for that decision that I created by expecting the compiler to resolve ambiguous code notwithstanding) than to ascribe it to datatype promotion/demotion. Typically, though, the compiler balks at pointer-integer conversion, and I would have expected something like that here, rather than silently do as it thought I said.

I think there should have been a warning somewhere, or an error, applied to the construct by the compiler. But alas, none was indicated.

I am aware that the compiler "tries" to do what it asked to do, and to try to make things fit, but if it's not clear, I'd rather have errors and warnings out the kazoo than to have it guess as to what is intended. And I know that the compiler is neither intelligent nor animate, and can only obey the rules given; I am at this point really only interested in understanding the rules that came into play here.