Error Message
nonstandard extension used : zero-sized array in struct/union
A structure or union contains an array with zero size.
Level-2 warning when compiling a C++ file and a Level-4 warning when compiling a C file.
Example
// C4200.cpp
// compile with: /W2
#include <stdio.h>
struct A {
int a[0]; // C4200
};
int main() {
}