All combinations of 0's and 1's in 128 bit character array?

[itsmeandnobodyelse]

Mhm, that would work fine if I was just printing, but I need to actually store it in a 16 byte character array and pass it to another function.

And calling next_permutation on the character array directly would just swap the different combinations of bytes instead of the individual bits, wouldn't it??

The vector already holds an internal 16-byte elements array.

If you do

     unsigned char * p = (unsigned char *)&v[0];
     some_otherfunction_expecting_a_16bytes_array(p);

where v is one of the permutations you got the pointer p would point to a 16-elements array.

If you want to copy the array to fixed-sized char array, you would/could do

     unsigned char arr[16] = { '\0' };
     unsigned char * p = (unsigned char *)&v[0];
     memcpy(arr, p, min(sizeof(arr), v.size() * sizeof(v[0])));

The min is only to make sure that the vector really has 16 elements of type char, same as the arr.

Regards, Alex