Macro definition ARRAY_SIZE

Question

I encountered the following macro definition when reading the globals.h in the Google V8 project.

// The expression ARRAY_SIZE(a) is a compile-time constant of t         


        

Answer 1

If sizeof(a) / sizeof(*a) has some remainder (i.e. a is not an integral number of *a) then the expression would evaluate to 0 and the compiler would give you a division by zero error at compile time.

I can only assume the author of the macro was burned in the past by something that didn't pass that test.