/in/ex7.c: In function 'IsEmptyList':
/in/ex7.c:40:15: error: invalid operands to binary == (have 'node_t {aka struct node}' and 'void *')
      if (*head==NULL){
          ~~~~~^~
/in/ex7.c:44:1: error: control reaches end of non-void function [-Werror=return-type]
 }
 ^
cc1: all warnings being treated as errors