foo.cc: In function ‘int main()’:
foo.cc:8:12: error: ‘make_unique’ was not declared in this scope
    8 |     auto A=make_unique<vector<int>>();
      |            ^~~~~~~~~~~
foo.cc:8:12: note: ‘std::make_unique’ is only available from C++14 onwards
foo.cc:8:34: error: expected primary-expression before ‘>’ token
    8 |     auto A=make_unique<vector<int>>();
      |                                  ^~
foo.cc:8:37: error: expected primary-expression before ‘)’ token
    8 |     auto A=make_unique<vector<int>>();
      |                                     ^
foo.cc:12:41: error: expected primary-expression before ‘>’ token
   12 |     auto B=make_unique<unordered_set<int>>();
      |                                         ^~
foo.cc:12:44: error: expected primary-expression before ‘)’ token
   12 |     auto B=make_unique<unordered_set<int>>();
      |                                            ^
foo.cc:15:34: error: expected primary-expression before ‘>’ token
   15 |     auto C=make_unique<vector<int>>();
      |                                  ^~
foo.cc:15:37: error: expected primary-expression before ‘)’ token
   15 |     auto C=make_unique<vector<int>>();
      |                                     ^
foo.cc:17:45: error: ‘e’ was not declared in this scope
   17 |     for(auto p=A->data(), *e=p+A->size(); p<e; ++p)
      |                                             ^