Adding data inside unordered_map inside a class - c++

Question

I have a class Citydata, defined in .hh file
struct City_details {
string name;
int taxrate;
};
class Citydata {
public:
bool add_data(string id, string name, int taxrate)
//other member functions...
private:
unordered_map<id, City_details> info_map;
I have trouble implementing the add_data function in .cc file. Here is my try.
bool Citydata::add_data(string id, string name, int taxes) {
if ( info_map.find(id) == info_map.end()) {
City_details dataload;
dataload.name = name;
dataload.taxrate = taxes;
info_map[id] = dataload;
return true;
}
else return false;
}
When I test this, I cannot see any data added the way I wanted. Instead I see one completely empty entry (default empty values), and one entry with right id (the key) but no data added to the parameters. Each time I call add_data, it creates similar pair of one completely empty key-data member, then one with right id and otherwise empty data.
The original program is much longer than this, so problem might persist there too, but I wonder if my approach is flawed by design.

Answer 1

I have made some modifications that makes your program work.
First you should replace unordered_map<id, City_details> info_map; with unordered_map<std::string, City_details> info_map;
Second you had a missing semicolon ; for you add_data member function declaration inside the class which you might have missed while copy pasting the code here on Stackoverflow.
Third i have avoided the use of using namespace std;.
main.cpp
#include <iostream>
#include "file.h"
int main()
{
Citydata c1;
c1.add_data("id1","Georgia", 34);
c1.add_data("id2", "California", 32);
c1.add_data("id3","Texas", 23);
//lets print out the element of info_map
for(auto &it:c1.info_map)
std::cout << it.first <<" "<<it.second.name<<" "<<it.second.taxrate<<std::endl;
return 0;
}
file.h
#pragma once
#include <unordered_map>
#include <string>
struct City_details {
std::string name;
int taxrate;
};
class Citydata {
public:
bool add_data(std::string id, std::string name, int taxrate);
//other member functions...
//private:
std::unordered_map<std::string, City_details> info_map;//the first tempate argument should be int and not id
};
file.cpp
#include "file.h"
bool Citydata::add_data(std::string id, std::string name, int taxes) {
if ( info_map.find(id) == info_map.end()) {
City_details dataload;
dataload.name = name;
dataload.taxrate = taxes;
info_map[id] = dataload;
return true;
}
else return false;
}