$> g++ test.c -lvector
test.c: In function `int main(int, char**)':
test.c:6: error: `vector' undeclared (first use this function)
test.c:6: error: (Each undeclared identifier is reported only once for each
   function it appears in.)
test.c:6: error: parse error before `>' token
test.c:7: error: `a' undeclared (first use this function)