[Programming bug] cannot convert ‘ns3::QueueItem*’ to ‘ns3::Packet*’ in initialization.

[Frank Wang]

I was writing my module, and I have some code like this :

Ptr<Queue> my_queue;
Ptr<Packet> p_pkt;
my_queue = CreateObject<DropTailQueue>()
p_pkt = my_queue->Dequeue();

The module conform the organization this page asked.

In my top-wscript, I have this : module.cxxflags = ['-std=c++11', '-Wall', '-Wextra', '-fpermissive', '-w']

Could anyone help me with this?

Full bug report is here :

In file included from ./ns3/attribute.h:25:0,
                 from ./ns3/attribute-accessor-helper.h:23,
                 from ./ns3/core-module.h:12,
                 from ../src/ns3dtn-bit/model/ns3dtn-bit.h:5,
                 from ../src/ns3dtn-bit/model/ns3dtn-bit.cc:3:
./ns3/ptr.h: In instantiation of ‘ns3::Ptr<T>::Ptr(const ns3::Ptr<U>&) [with U = ns3::QueueItem; T = ns3::Packet]’:
../src/ns3dtn-bit/model/ns3dtn-bit.cc:75:35:   required from here
./ns3/ptr.h:746:27: error: cannot convert ‘ns3::QueueItem*’ to ‘ns3::Packet*’ in initialization
   : m_ptr (PeekPointer (o))
                           ^
./ns3/ptr.h: In instantiation of ‘ns3::Ptr<T>::Ptr(const ns3::Ptr<U>&) [with U = ns3::Packet; T = ns3::QueueItem]’:
../src/ns3dtn-bit/model/ns3dtn-bit.cc:88:64:   required from here
./ns3/ptr.h:746:27: error: cannot convert ‘ns3::Packet*’ to ‘ns3::QueueItem*’ in initialization

[Luciano Jerez Chaves]

Hi,

You can check the API doxygen in cases like that.

As you can see here https://www.nsnam.org/docs/release/3.26/doxygen/classns3_1_1_queue_item.html the QueueItem is an object that carries a packet inside it. You cannot cast it directly. You can use the member function to get the packet.

Cheers,

[Frank Wang]

Thanks for your time, I thought I got the wrong API page here.

Your advice really helps!!
在 2017年2月24日星期五 UTC+8上午7:38:25，Luciano Jerez Chaves写道：