Question

struct air_message
{    
    deque<int> path;

    int dest_region;
    int dest_airport;
    int next_region;

    int msg_from;
};

I have this structure. And I have this code

deque<int> p = graph->get_shortest_path(source_region, dest_region);                    
m->path = p;

At this line

m->path = p;

I am getting a segmentation fault error (‘m’ is a pointer of the air_message structure).

Answer 1

You need to examine the code that allocates m. Your problem here isn’t with the deque itself, it’s because m is not a valid pointer.

For example, if the only code you have is:

struct air_message *m;
deque<int> p = graph->get_shortest_path (blah, blah);                    
m->path = p;

then yes, m will not be valid.