Create a shared-memory vector of strings

Question

I am trying to create a class managing a shared-memory vector of (std)strings.

typedef boost::interprocess::allocator

        

Answer 1

From the docs.

#include 
#include 
#include 
#include 

int main ()
{
   using namespace boost::interprocess;
   //Typedefs
   typedef allocator
      CharAllocator;
   typedef basic_string, CharAllocator>
      MyShmString;
   typedef allocator
      StringAllocator;
   typedef vector
      MyShmStringVector;

   //Open shared memory
   //Remove shared memory on construction and destruction
   struct shm_remove
   {
      shm_remove() { shared_memory_object::remove("MySharedMemory"); }
      ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
   } remover;

   managed_shared_memory shm(create_only, "MySharedMemory", 10000);

   //Create allocators
   CharAllocator     charallocator  (shm.get_segment_manager());
   StringAllocator   stringallocator(shm.get_segment_manager());

   //This string is in only in this process (the pointer pointing to the
   //buffer that will hold the text is not in shared memory).
   //But the buffer that will hold "this is my text" is allocated from
   //shared memory
   MyShmString mystring(charallocator);
   mystring = "this is my text";

   //This vector is only in this process (the pointer pointing to the
   //buffer that will hold the MyShmString-s is not in shared memory).
   //But the buffer that will hold 10 MyShmString-s is allocated from
   //shared memory using StringAllocator. Since strings use a shared
   //memory allocator (CharAllocator) the 10 buffers that hold
   //"this is my text" text are also in shared memory.
   MyShmStringVector myvector(stringallocator);
   myvector.insert(myvector.begin(), 10, mystring);

   //This vector is fully constructed in shared memory. All pointers
   //buffers are constructed in the same shared memory segment
   //This vector can be safely accessed from other processes.
   MyShmStringVector *myshmvector =
      shm.construct("myshmvector")(stringallocator);
   myshmvector->insert(myshmvector->begin(), 10, mystring);

   //Destroy vector. This will free all strings that the vector contains
   shm.destroy_ptr(myshmvector);
   return 0;
}