You can use using = instead of typedef using namespace std; using foo_bar_xref = vector<unordered_map<string, pair<string, string>>; foo_bar_xref foo( v

You can use using = instead of typedef using namespace std; using foo_bar_xref = vector<unordered_map<string, pair<string, string>>; foo_bar_xref foo( vector<vector<int>> x, unordered_map<string, string> y);