Hello all! My programm: `--# cat test_boost.hpp #include <boost/graph/adjacency_list.hpp> #include <boost/graph/rmat_graph_generator.hpp> #include <boost/random/linear_congruential.hpp> typedef boost::adjacency_list<>Graph; typedef boost::unique_rmat_iterator<boost::minstd_rand, Graph> RMATGen; int main() { boost::minstd_rand gen; // Create graph with 100 nodes and 400 edges Graph g(RMATGen(gen, 100, 400, 0.57, 0.19, 0.19, 0.05), RMATGen(), 100); return 0; } `--# mpic++ test_boost.hpp -I./boost/boost/graph/ -I./boost/ -I./boost/boost/random/ -o test_boost /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../x86_64-linux-gnu/crt1.o: In function `_start': (.text+0x20): undefined reference to `main' collect2: error: ld returned 1 exit status what's wrong ?