store humans in linked-list and some attributes of them outside, delete multiple at once

llist-attr.cpp

//
//  main.cpp
//  test_humans
//
//  Created by Sean Wu on 5/31/18.
//  Copyright © 2018 Sean Wu. All rights reserved.
//

#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <memory>
#include <math.h>

class person {
public:
    person(const std::string& name_, const bool alive_) : name(name_), alive(alive_) {
        std::cout << name << " being born at " << this << std::endl;
    };
    ~person(){
        std::cout << name << " being killed at " << this << std::endl;
    };
    
    /* move operators */
    person(person&&) = default;
    person& operator=(person&&) = default;
    
    /* copy operators */
    person(person&) = delete;
    person& operator=(person&) = delete;
    
    std::string get_name(){
        return name;
    };
    
    bool alive;
    
private:
    std::string name;
};


int main(int argc, const char * argv[]) {

    std::list<std::unique_ptr<person> > vec1;
    std::vector<int > vec2;
    
    vec1.emplace_back(std::make_unique<person>("alice",false));
    vec2.emplace_back(1);
    
    vec1.emplace_back(std::make_unique<person>("bob",true));
    vec2.emplace_back(2);
    
    vec1.emplace_back(std::make_unique<person>("john",false));
    vec2.emplace_back(3);
    
    vec1.emplace_back(std::make_unique<person>("shirley",true));
    vec2.emplace_back(4);
    
    vec1.emplace_back(std::make_unique<person>("charley",false));
    vec2.emplace_back(5);
    
    std::cout << " --- erasing --- " << std::endl;
    size_t i = 0;
    for(auto it=vec1.begin(); it != vec1.end(); ++it){
        if(!it->get()->alive){
            vec1.erase(it);
            vec2.erase(vec2.begin() + i);
        } else {
            i++;
        }
    }
    std::cout << " --- done --- " << std::endl;
    
    
    i = 0;
    for(auto it=vec1.begin(); it != vec1.end(); ++it){
        std::cout << "name : " << it->get()->get_name() << " alive : " << it->get()->alive;
        std::cout << " val : " << vec2[i] << " -- \n";
        i++;
    }
    
    std::cout << " --- exiting program --- " << std::endl;
    
    return 0;
}