Question

I have

typedef std::queue<MyObject*> InputQueue;
std::vector<InputQueue> inp_queue;

Now what I want to do is define at runtime say 5 queues and place data on those queues like

inp_queue[1].push(new MyObject());

etc.

I got it to compile, but it core dumps right away. I guess I need to actually add the queues to the vector first (they don’t get created automatically like a map). How do I add a queue without it being a pointer to a queue?

EDIT:

I should really have pointed out that the queue class I am using is not std::queue but this one: http://www.justsoftwaresolutions.co.uk/threading/implementing-a-thread-safe-queue-using-condition-variables.html

I didn’t expect the compiler to complain about it otherwise I would have stated it up front.

Unfortunately when I compile the application I get this compilation error.

g++ test.cpp
In file included from /usr/include/c++/4.4/deque:63,
                 from /usr/include/c++/4.4/queue:61,
                 from concurrentqueue.h:3,
                 from test.cpp:1:
/usr/include/c++/4.4/bits/stl_construct.h: In function ‘void std::_Construct(_T1*, const _T2&) [with _T1 = concurrent_queue<Packet*>, _T2 = concurrent_queue<Packet*>]’:
/usr/include/c++/4.4/bits/stl_uninitialized.h:187:   instantiated from ‘static void std::__uninitialized_fill_n<<anonymous> >::uninitialized_fill_n(_ForwardIterator, _Size, const _Tp&) [with _ForwardIterator = concurrent_queue<Packet*>*, _Size = long unsigned int, _Tp = concurrent_queue<Packet*>, bool <anonymous> = false]’
/usr/include/c++/4.4/bits/stl_uninitialized.h:223:   instantiated from ‘void std::uninitialized_fill_n(_ForwardIterator, _Size, const _Tp&) [with _ForwardIterator = concurrent_queue<Packet*>*, _Size = long unsigned int, _Tp = concurrent_queue<Packet*>]’
/usr/include/c++/4.4/bits/stl_uninitialized.h:318:   instantiated from ‘void std::__uninitialized_fill_n_a(_ForwardIterator, _Size, const _Tp&, std::allocator<_Tp2>&) [with _ForwardIterator = concurrent_queue<Packet*>*, _Size = long unsigned int, _Tp = concurrent_queue<Packet*>, _Tp2 = concurrent_queue<Packet*>]’
/usr/include/c++/4.4/bits/stl_vector.h:1035:   instantiated from ‘void std::vector<_Tp, _Alloc>::_M_fill_initialize(size_t, const _Tp&) [with _Tp = concurrent_queue<Packet*>, _Alloc = std::allocator<concurrent_queue<Packet*> >]’
/usr/include/c++/4.4/bits/stl_vector.h:230:   instantiated from ‘std::vector<_Tp, _Alloc>::vector(size_t, const _Tp&, const _Alloc&) [with _Tp = concurrent_queue<Packet*>, _Alloc = std::allocator<concurrent_queue<Packet*> >]’
test.cpp:18:   instantiated from here
/usr/include/c++/4.4/bits/stl_construct.h:74: error: no matching function for call to ‘concurrent_queue<Packet*>::concurrent_queue(const concurrent_queue<Packet*>&)’
concurrentqueue.h:12: note: candidates are: concurrent_queue<Packet*>::concurrent_queue()
concurrentqueue.h:12: note:                 concurrent_queue<Packet*>::concurrent_queue(concurrent_queue<Packet*>&)

Answer 1

You have not allocated any of the 5 queues. Try:

typedef std::queue<MyObject*> InputQueue;
std::vector<InputQueue> inp_queue(5);
inp_queue[1].push(new MyObject());

Also not that std::vector uses indices starting from 0, so to insert into the first queue:

inp_queue[0].push(new MyObject());

Follow-up to your edit: The concurrent queue does not seem to have a copy constructor. This means you can not put it in any standard container because it does not satisfy the requirements. The container’s value-type must be copy-constructible and copy-assignable.