Initialization of Objects with Static Storage Duration in C vs C++ [duplicate]

Answer 1

Your code is not legal C.

If your compiler compiles it without a diagnostic,
your compiler is not a C compiler

You must use constants to initialize a variable.

In your code, the initializer expression ( i + 1 ) is not a constant.

This violates 6.7.8/4:

All the expressions in an initializer [...] shall be constant expressions or string literals.