Hi everyone, I wrote a simple program to use a concurrent_priority_queue. I followed the sample code. Here's all I have right now. #include "/tbb/concurrent_priority_queue.h" #include using namespace std; using namespace tbb; typedef std::pair vertex_rec; class compare_f { public: bool operator()(const vertex_rec& u, const vertex_rec& v) const { return u.second>v.second; } }; concurrent_priority_queue open_set; Compiling this gives me an error. /tmp/ccIzLsvO.o: In function `tbb::cache_aligned_allocator >::deallocate(std::pair*, unsigned long)'\\ : tbb.C:(.text._ZN3tbb23cache_aligned_allocatorISt4pairImdEE10deallocateEPS2_m[tbb::cache_aligned_allocator >::deallocate(std\\ ::pair*, unsigned long)]+0x19): undefined reference to `tbb::internal::NFS_Free(void*)' collect2: ld returned 1 exit status So the linker cannot find a reference to NFS_Free? Can anyone help me compile this? Many thanks.