error: linker command failed with exit code 1 (use -v to see invocation) c++ clion

Question

Im using c++. Does anyone know how i can fix this?

Undefined symbols for architecture x86_64: "Template::Template(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >, int)", referenced from: _main in main.cpp.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

basically writing a merge sort algorithm

main:

int main() {
  int SORT_MAX_SIZE = 16;
  int userNumInput;
  std::string userDataType;
  std::cout << "What type of data would you like to enter options: int, string "
               "or Dollar objects" << std::endl;
  std::cin >> userDataType;
  std::cout << "Please enter the number of elements you would like to enter"
            << std::endl;
  std::cin >> userNumInput;
  if (userNumInput > SORT_MAX_SIZE) {
    std::cout << "Please enter the number of elements less then 16"<< std::endl;
    std::cin >> userNumInput;
  }
  Template createTemp = Template(userDataType, userNumInput);
  int userData; //todo:how to change this to a different data type
  for(int i = 0; i < userNumInput; i++) {
    std::cout << "Please enter an element for the spot " + std::to_string(i) <<
              std::endl;
    std::cin >> userData;
    createTemp.userArray[i] = userData;
  }
  RecurMergeSort(createTemp.userArray, userNumInput);
  std::cout << "Sorted Array:" << std::endl;
  print(createTemp.userArray, userNumInput);
  return 0;
}

template class:

#include "Template.h"
#include "Dollar.h"

Template::Template(const std::string d, int a) {
  dataType = d;
  numInput = a;
}

void Template::createTemplate() {
  //create an array based on the information provided above
  if (dataType == "int") {
    int userArray[numInput];
  } else if (dataType == "Dollar objects") {
    Dollar userArray[numInput];
  } else if (dataType == "string") {
    std::string userArray[numInput];
  }
}