Checking if a sequence container is contiguous in memory

Question

Is there a way to check if a sequence container is contiguous in memory? Something like:

#include 
#include 
#include 

        

Answer 1

No. The C++ Standard guarantees there are no false negatives. (i.e., std::vector, std::string, std::array, and basic arrays are promised to be stored contiguously).

However, the C++ Standard doesn't guarantee there are no false positives.

int main() {
   std::unique_ptr n1(new Node);
   std::unique_ptr n2(new Node);
   n1->next = n2; // n1 and n2 might be contiguous, but might not be
}

Thus, your type trait could be wrong some of the time. If it's wrong some of the time, it's not a type trait; rather, it's an instance trait.