Question

I have to create a function that takes in a vector of unknown item types.
Here is my code:

template <typename S>
void printVector(vector<S*> c){
   typename vector<S>::const_iterator A = c.begin();
   for (int A; A != c.end(); A++){
       cout<<c[A]<<" ";
   }
   cout<<endl;
}

In my main class here is my vector and function call:

vector<int> x;
int j=5;
for(int i=0;i<j;i++){
    x.push_back(num[i]);
}
printVector(x);

When I try to compile this code I get these errors:

exercise1_1.cpp: In function ‘int main()’:
exercise1_1.cpp:33:15: error: no matching function for call to ‘printVector(std::vector<int>&)’
exercise1_1.cpp:33:15: note: candidate is:
exercise1_1.cpp:13:7: note: template<class S> void printVector(std::vector<S*>)

Answer 1

template <typename S>
void  printVector(const std::vector<S>& c){
   typename std::vector<S>::const_iterator A = c.begin();
   for (; A != c.end(); A++){
       std::cout<<*A<<" ";
   }
   std::cout<<"\n";
}

Fixes:

• Your function was declared to take a vector<S*> but you obviously want it to take vector<S>.
  • Your main function invoked print_vector with an argument of std::vector<int>. Since an int is not an S* for any type of S, the template did not apply.
• You have redeclared A when you intended to use only the first declaration.
• You conflated indexed access to the vector with access through the iterator.
  • If you have an int: c[i]
  • If you have an iterator: *it

Less critical fixes:

• Avoid using namespace std;
• Never use std::endl when you mean "\n".
• You should pass the parameter by const reference, not by value