foo.cc: In function ‘int main()’:
foo.cc:10:30: error: template argument 1 is invalid
   10 |     vector<int>*b=new vector<int;>; b->reserve(m);
      |                              ^~~
foo.cc:10:30: error: template argument 2 is invalid
foo.cc:10:34: error: expected primary-expression before ‘>’ token
   10 |     vector<int>*b=new vector<int;>; b->reserve(m);
      |                                  ^
foo.cc:10:35: error: expected primary-expression before ‘;’ token
   10 |     vector<int>*b=new vector<int;>; b->reserve(m);
      |                                   ^
foo.cc:14:12: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   14 |     while(i<a->size()&&j<b->size())
      |           ~^~~~~~~~~~
foo.cc:14:25: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   14 |     while(i<a->size()&&j<b->size())
      |                        ~^~~~~~~~~~
foo.cc:16:12: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   16 |     while(i<a->size()) c->push_back((*a)[i++]);
      |           ~^~~~~~~~~~
foo.cc:17:12: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   17 |     while(j<b->size()) c->push_back((*b)[j++]);
      |           ~^~~~~~~~~~