Saving map of structures

Asked Feb 26 '21 at 14:34

Active Feb 26 '21 at 14:34

Viewed 39 times

How i can save map of structure in c++ to txt? I have that code.

#include <bits/stdc++.h>
#include <fstream>
using namespace std;

struct category {
        int id;
        std::string name;
};

map<int, category> categories;

int main() {
        category tmp1 = { 1, "First category" };
        category tmp2 = { 2, "Second category" };

        categories[1] = tmp1;
        categories[2] = tmp2;
        fstream file;
        file.open("test.txt", ios::out, ios::app);
        file << categories[1] << endl << categories[2];
        file.close();
}

I have error in vscode but i cant read it.

asked Feb 26 '21 at 14:34

boldog

1

you cannot read the error message? Why not? – 463035818_is_not_an_ai Feb 26 '21 at 14:35
Instead of creating a bunch of junk variables and then force-assigning into a `std::map`, why not just [provide that data to the constructor direcrtly](https://en.cppreference.com/w/cpp/container/map/map) or at the least [`emplace`](https://en.cppreference.com/w/cpp/container/map/emplace) them? – tadman Feb 26 '21 at 14:42
i dont understand it – boldog Feb 26 '21 at 14:51
it is so long and i just dont know what is in it – boldog Feb 26 '21 at 14:53
i suggest you to forget about the map for a moment, because the map isnt the problem. C++ does not provide an automagic way to print custom types to a file (or stdout, or anywhere). How you can do it is explained in the duplicate – 463035818_is_not_an_ai Feb 26 '21 at 14:58
where is duplicate (sry im new) – boldog Feb 26 '21 at 15:04

Saving map of structures

0 Answers0