Файлы, структуры

struct Operation {
    int sum;
    double rate;
    Operation(double s, double r) : sum(s), rate(r) {}
};

#include <iostream>
#include <string>
#include <vector>
#include <fstream>
 
using namespace std;
 
struct Operation {
    int sum;
    double rate;
    Operation(double s, double r) : sum(s), rate(r) {}
};
 
int main() {
    vector <Operation> operations = {
        Operation(21, 12.5),
        Operation(23.5, 1.6),
        Operation(21.5, 3)
    };
    string path = "text.txt";
    ofstream fout;
    fout.open(path);
    if(fout.is_open()) {
        for(int i = 0; i < operations.size(); i++) {
            fout << operations[i].sum << " " << operations[i].rate << endl;
        }
    }
    fout.close();
    vector <Operation> new_operations;
    double rate;
    int sum;
    ifstream fin(path);
    if(fin.is_open()){
        while (fin >> sum >> rate){
            new_operations.push_back(Operation(sum, rate));
        }
    }
    fin.close();
    for(int i = 0; i < new_operations.size(); i++) {
        cout << new_operations[i].sum << " " << new_operations[i].rate << endl;
    }
    return 0;
}

struct Operation {
    int sum;
    double rate;
    Operation(double s, double r) : sum(s), rate(r) {}
};

    Operation(double s, double r) : sum(s), rate(r) {}

    Operation(double s, double r)
    {
        sum=s;
        rate=r;
    }

    Operation(double s, double r) : sum{s}, rate{r} {}