Is the data in nested std::arrays guaranteed to be contiguous?

Question

Is the data in std::array, M> guaranteed to be contiguous? For example:

#include 
#include 

        

Answer 1

They are very likely contiguous. If they are not, the compiler is actively fighting you there. There's no guarantee it won't insert padding but there's hardly a reason for it.

Is the assert guaranteed to succeed?

data[7] is an out-of-bounds access (undefined behaviour). The inner array object has only seven elements, so index 7 is not valid.