Configure ns-3 with

$ CXX="clang++" CC="clang" ./waf configure --enable-examples --enable-tests

clang version: 3.7.0
$ clang -v
clang version 3.7.0 (tags/RELEASE_370/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-unknown-linux-gnu/5.2.0
Found candidate GCC installation: /usr/bin/../lib64/gcc/x86_64-unknown-linux-gnu/5.2.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-unknown-linux-gnu/5.2.0
Found candidate GCC installation: /usr/lib64/gcc/x86_64-unknown-linux-gnu/5.2.0
Selected GCC installation: /usr/bin/../lib64/gcc/x86_64-unknown-linux-gnu/5.2.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

The error is the following:

../src/nix-vector-routing/examples/nms-p2p-nix.cc:79:9: error: 'delete' applied to a pointer that was allocated with 'new[]'; did you mean 'delete[]'? [-Werror,-Wmismatched-new-delete]
        delete p;
        ^
              []
../src/nix-vector-routing/examples/nms-p2p-nix.cc:149:26: note: in instantiation of member function 'Array2D<ns3::NodeContainer>::~Array2D' requested here
  Array2D<NodeContainer> nodes_net0(nCN, 3);
                         ^
../src/nix-vector-routing/examples/nms-p2p-nix.cc:69:51: note: allocated with 'new[]' here
    Array2D (const size_t x, const size_t y) : p (new T*[x]), m_xMax (x) 
                                                  ^
../src/nix-vector-routing/examples/nms-p2p-nix.cc:79:9: error: 'delete' applied to a pointer that was allocated with 'new[]'; did you mean 'delete[]'? [-Werror,-Wmismatched-new-delete]
        delete p;
        ^
              []
../src/nix-vector-routing/examples/nms-p2p-nix.cc:160:35: note: in instantiation of member function 'Array2D<ns3::Ipv4InterfaceContainer>::~Array2D' requested here
  Array2D<Ipv4InterfaceContainer> ifs0(nCN, 3);
                                  ^
../src/nix-vector-routing/examples/nms-p2p-nix.cc:69:51: note: allocated with 'new[]' here
    Array2D (const size_t x, const size_t y) : p (new T*[x]), m_xMax (x) 
                                                  ^
../src/nix-vector-routing/examples/nms-p2p-nix.cc:79:9: error: 'delete' applied to a pointer that was allocated with 'new[]'; did you mean 'delete[]'? [-Werror,-Wmismatched-new-delete]
        delete p;
        ^
              []
../src/nix-vector-routing/examples/nms-p2p-nix.cc:266:35: note: in instantiation of member function 'Array2D<ns3::NetDeviceContainer>::~Array2D' requested here
      Array2D<NetDeviceContainer> ndc2LAN(7, nLANClients);
                                  ^
../src/nix-vector-routing/examples/nms-p2p-nix.cc:69:51: note: allocated with 'new[]' here
    Array2D (const size_t x, const size_t y) : p (new T*[x]), m_xMax (x) 
                                                  ^
3 errors generated.


Patching is trivial.