將對象推到列表上的分段錯誤

Question

我不知道如何/爲什麼我繼續得到分段錯誤。我的代碼在5分鐘前工作正常。我根本沒有改變現有的代碼，只增加了更多的功能。我可以進入addName函數，直到我嘗試將新對象推送到列表中爲止。早些時候，我進入了「添加名稱喬希戴維斯」，它的工作就像一個魅力，現在我每次都得到一個seg錯誤。我究竟做錯了什麼？？？？

#include <iostream> 
#include <string> 
#include <list> 
#include <sstream> 
using namespace std; 

// class declaration 
class Contact 
{ 
    private: 
     // member declarations 
    string firstname, lastname, name, name_sort, uid, address, city, state, zip, birthdate, wedding_date, death_date; 
    list<Contact>::iterator spouse; 
    list<Contact*> children; 
public: 
    // constructor 
    Contact(string nm, string f_nm, string l_nm, int IDcount) 
    { 
     // stream declaration for concatenation 
     stringstream s_strm; 

     firstname = f_nm; 
     lastname = l_nm; 
     name = f_nm + " " + l_nm; 
     name_sort = nm; 
     spouse->name = "NONE_LISTED"; 
     address = "NONE_LISTED"; 
     city = "NONE_LISTED"; 
     state = "NONE_LISTED"; 
     zip = "NONE_LISTED"; 
     birthdate = "NONE_LISTED"; 
     wedding_date = "NONE_LISTED"; 
     death_date = "NONE_LISTED"; 

     if (IDcount < 10) 
     { 
      string ID = "ID00"; 
      s_strm << ID << IDcount; 
      uid = s_strm.str(); 
     } 
     else if (IDcount < 100) 
     { 
      string ID = "ID0"; 
      s_strm << ID << IDcount; 
      uid = s_strm.str(); 
     } 
     else 
     { 
      string ID = "ID"; 
      s_strm << ID << IDcount; 
      uid = s_strm.str(); 
     } 
    } 

    // get functions 
    string getFirstname() { return firstname; } 
    string getLastname() { return lastname; } 
    string getName() { return name; } 
    string getNamesort() { return name_sort; } 
    string getUid() { return uid; } 
}; 

int main (void) 
{ 
    // list declaration 
    list<Contact> address_book; 

// variable declarations 
ifstream f_in; 
string cmd; 
int IDcount = 1; 

// print out welcome message and menu 
cout << "\n\t\tWelcome to Address Book 2.0!\n" 
    << "\nAVAILABLE COMMANDS:\n" 
     << "\tadd name <name> ==> Add a new name (First Last) to the Address Book\n" 
     << "\tadd spouse <uid> <name> ==> Add spouse of <uid> (First Last) to the Address Book\n" 
     << "\tadd child <uid> <name> ==> Add a child of <uid> (First Last) to the Address Book\n" 
     << "\tadd address1 <uid> <address> ==> Add/change the address for <uid>\n" 
     << "\tadd city <uid> <city> ==> Add/change the city for <uid>\n" 
     << "\tadd state <uid> <state> ==> Add/change the state for <uid>\n" 
     << "\tadd zip <uid> <zipcode> ==> Add/change the zipcode for <uid>\n" 
     << "\tadd date_birth <uid> <ddmmyyyy> ==> Add/change the birthday for <uid>\n" 
     << "\tadd date_wedding <uid> <ddmmyyyy> ==> Add/change the wedding day for <uid>\n" 
     << "\tadd date_death <uid> <ddmmyyyy> ==> Add/change the date of death for <uid>\n" 
     << "\tsearch <name> ==> searches for name (First Last) and returns the <uid>, if found\n" 
     << "\tprint all ==> Prints a list of ALL of the names in the Address Book with their <uid> <name>\n" 
     << "\tprint <uid> ==> Prints all of the fields for <uid>\n" 
     << "\tfile ==> user is prompted for a filename that contains correctly formatted commands\n" 
     << "\t    --- the file must be in CSV format with one full command per line\n" 
     << "\tquit ==> processing complete\n\n" 
     << "cmd> "; 


// obtain command, call appropriate function, loop if desired 
do 
{ 
    getline(cin, cmd); 

    if (cmd.compare(0, 9, "add name ") == 0 || cmd.compare(0, 9, "ADD NAME ") == 0) 
    { 
     addName(address_book, cmd, IDcount); 
     cout << "\ncmd> "; 
    } 

    else 
    { 
     cout << "ERROR: Invalid input. Either you entered an unrecognized command or used an incorrect number of parameters." << endl; 
     cout << "\ncmd> "; 
    } 

} while (cmd != "quit" && cmd != "QUIT"); 

return 0; 
} 

void addName(list<Contact>& address_book, string cmd, int& IDcount) 
{ 
// variable declarations 
string f_name, l_name, nm; 
bool duplicate = false; 
list<Contact>::iterator it; 

if (cmd.length() > 9) // ensure that there is another parameter after "add name " 
{ 
    cmd.erase(0, 9); // erase the command portion of the line input by the user, leaving only the name 
    // http://www.cplusplus.com/reference/string/string/substr/ 
    size_t pos = cmd.find(" "); // find the position of the space between the first and last name 
    l_name = cmd.substr(pos + 1); // get the last name and assign it to the variable 

    cmd.erase(pos, -1); // erase the last name (http://www.cplusplus.com/reference/string/string/npos/) 
    f_name = cmd; // assign the first name to the variable 
    nm = l_name + " " + f_name; // assign last name, first name to a variable for sorting 

    // search for duplicates if the list is not empty 
    if (IDcount != 1) 
    { 
     for (it = address_book.begin(); it != address_book.end(); ++it) 
     { 
      if (it->getNamesort() == nm) // if duplicate is found, output error message and update the bool so that it will not be added to the list 
      { 
       cout << "DUPLICATE: " << it->getName() << " UID: " << it->getUid() << endl; 
       duplicate = true; 
      } 
     } 
    } 

    if (duplicate == false) // no duplicates found 
    { 
     address_book.push_front(Contact(nm, f_name, l_name, IDcount)); // create a new object in Contact class and add to the beginning of the list 
     // NEVER MAKE IT PAST HERE - SEGMENTATION FAULT 
     IDcount++; 
     it = address_book.begin(); 
     cout << "ADDED: " << it->getName() << " UID: " << it->getUid() << endl; 
     address_book.sort(comp_by_name_sort); // sort the entries in the list alphabetically by last name, then first name 
    } 
} 

else // no input after "add name " 
{ 
    cout << "ERROR: Not enough command parameters." << endl; 
} 
} 

Answer 1

list<Contact>::iterator spouse; <- iterator points to nothing 
    list<Contact*> children; 
public: 
    // constructor 
    Contact(string nm, string f_nm, string l_nm, int IDcount) 
    { 
     // stream declaration for concatenation 
     stringstream s_strm; 

     firstname = f_nm; 
     lastname = l_nm; 
     name = f_nm + " " + l_nm; 
     name_sort = nm; 
     spouse->name = "NONE_LISTED"; <- act as if spouse points to valid object 

我不知道你怎麼想的是最後一行的做法，但它顯然是無效的。迭代器spouse不引用任何有效的對象。