Функции С++. Как вывести значения?

Question

[users88888]

file.cpp

#include "iostream"
#include "CAuthorization.h"
#include "CAuthorizationXMLVisitor.h"
using namespace std;
using namespace tinyxml2;
using namespace Authorization;


vector <auth_handle> clients;
 CAuthorization userInformation;

int auth_init(auth_handle** handle)
{
    if (*handle == nullptr)
    {

        CAuthorizationData* data = new CAuthorizationData;

        userInformation.Load("auth.xml");
        *data = userInformation.Data();

        auth_handle *data_ = new auth_handle{};
        data_->mem = (void *)data;

        clients.push_back(*data_);

        char login [20];
        char password [20];

        int result=auth_checkpasswd(data_,login,password);

        printf("login: %s\n",login);
        printf("password:%s\n",password);

        *handle = data_;
    }
    return 0;

}

auth_checkpasswd(auth_handle* handle, char* login, char* passwd)
{
    for (const auto &User: userInformation.Data().users)
    {
        cout << "Login" << User.login << endl;
        cout << "Password" << User.password << endl; 
    }
  
}

CAuthorizationData.h

#ifndef CAUTHORIZATIONDATA_H
#define CAUTHORIZATIONDATA_H
#include <string>
#include <vector>

namespace Authorization
{
 struct CAuthorizationData 
 {
    struct CUserData
    {
        std::string _name;
        std::string _login;
        std::string _password;

        enum class RolesType
        {
            _none,
            _viewer,
            _operator,
            _engineer,
            _installer
        };

        std::vector<RolesType> _roles;
    };

    std::vector<CUserData> _users;
 };

}

#endif // CSETTINGSDATA_H

Знаю С++ на 2. Помогите в функции auth_checkpasswd(auth_handle* handle, char* login, char* passwd) вывести только логины и пароли, полученные из xml файла в функции int auth_init(auth_handle** handle) и записанные в data_.

auth.xml

<?xml version="1.0" encoding="UTF-8"?>
<authorization>
	<user name="user1"  login="login1" password="password1">
		<role type="viewer"/>
		<role type="engineer"/> 
		<role type="operator"/>  
	</user>
	<user name="user2"  login="login2" password="password2">
		<role type="operator"/>
	</user>
	<user name="user3"  login="login3" password="password3">
		<role type="engineer"/> 
	</user>
	<user name="user4"  login="login4" password="password4">
		<role type="installer"/>
		<role type="unknown"/> 
	</user>
</authorization>