Помогите с C++

При компиляции проекта у меня все выскакивает одна и та же ошибка, и я никак не могу разобраться:

Code:

error LNK2019: unresolved external symbol "public: __thiscall Laptops::Laptops(void)" (??0Laptops@@QAE@XZ) referenced in function "void __cdecl choice_i_fbo(void)" (?choice_i_fbo@@YAXXZ)	C:\Users\...\main.obj

Исходник:

Code:

#include <iostream>
#include <iomanip>
#include <climits>
#include <string>
#include <vector>
#include <cstdlib>
using namespace std;

void welcome();
void goodbye();
int choice_io();
void choice_i_fbo();
void choice_o_fbo();

class Item {
public:
	Item();
	virtual void input();
	virtual void output();
	static int intvalidation(int lowerbound, int upperbound) {
		double temp;
		cin >> temp; 
		while(cin.fail() || temp - int(temp) != 0 || temp < lowerbound || temp > upperbound) {
			cin.clear();
			cin.ignore(INT_MAX, '\n');
			cout << "The input must be a whole number between " << lowerbound << " and " << upperbound << ":" << endl;
			cin >> temp;
		}
		cin.clear();
		cin.ignore(INT_MAX, '\n');
		return int(temp);
	}
	static double doublevalidation(double lowerbound, double upperbound) {
		double temp;
		cin >> temp;
		while(cin.fail() || temp < lowerbound || temp > upperbound) {
			cin.clear();
			cin.ignore(INT_MAX, '\n');
			cout << fixed << setprecision(2) <<  "The input must between " << lowerbound << " and " << upperbound << ":";
			cin >> temp;
		}
		return temp;
	}
protected:
	double price;
	int units;
	string category;
	string location;
};

class Date {
public:
	Date() {
		day = 1;
		month = 1;
		year = 1900;
	}
	Date(int x) {
		day = x;
		month = 1;
		year = 1900;
	}
	Date(int x, int y) {
		day = x;
		month = y;
		year = 1900;
	}
	Date(int x, int y, int z) {
		day = x;
		month = y;
		year = z;
	}
	void output() {
		cout << day << "/" << month << "/" << year;
	}
	void input() {
		double temp;
		cout << "Please input a day between 1 and 30:";
		cin >> temp;
		while(cin.fail() || temp - int(temp) != 0 || temp < 1 || temp > 30) {
			if(cin.fail()) {
				cin.clear();
				cin.ignore(INT_MAX, '\n');
			}
			cout << "Please input a day between 1 and 30:";
			cin >> temp;
		}
		cin.clear();
		cin.ignore(INT_MAX, '\n');
		day = int(temp);
		cout << "Please input a month between 1 and 12:";
		cin >> temp;
		while(cin.fail() || temp - int(temp) != 0 || temp < 1 || temp > 12) {
			if(cin.fail()) {
				cin.clear();
				cin.ignore(INT_MAX,'\n');
			}
			cout << "Please input a month between 1 and 12:";
			cin >> temp;
		}
		cin.clear();
		cin.ignore(INT_MAX, '\n');
		month = int(temp);
		cout << "Please input a year between 1900 and 2100:";
		cin >> temp;
		while(cin.fail() || temp - int(temp) != 0 || temp < 1900 || temp > 2100) {
			if(cin.fail()) {
				cin.clear();
				cin.ignore(INT_MAX,'\n');
			}
			cout << "Please input a year between 1900 and 2100:";
			cin >> temp;
		}
		cin.clear();
		cin.ignore(INT_MAX,'\n');
		year=int(temp);
	}
private:
	int day;
	int month;
	int year;
};

class Computers : public Item {
public:
	Computers();
	string getname() {
		return name;
	}
	void input() {
		cout << "Type:";
		getline(cin, name);
		cout << "Price:";
		price = doublevalidation(0, 10E9);
		cout << "Units in stock:";
		units = intvalidation(0, INT_MAX);
		cout << "Guarantee Expiration date:\n";
		Guarantee_expiration.input();
		cout << "Location:";
		getline(cin, location);
		cout<<"Input the Operating System:\n";
		getline(cin, OS);
	}
	void output() {
		cout << fixed << endl;
		cout << "Type:" << name << setw(10) << "Price:" << setprecision(2) << price << "$" << setw(20) << "Item location:" << location << endl;
		cout << "Guarantee Expiration date:";
		Guarantee_expiration.output();
		cout << setw(20) << "Units in stock:" << units;
		cout<< "Operating System:";
		getline(cin, OS);
	}
protected:
	string name;
	Date Guarantee_expiration;
	string OS;
};

class Desktops : public Computers {
public:
	Desktops();	
	void input() {
		Computers::input();
		cout << "Enter the size of the Graphich Card:";
		cin >> Graphichcard;
		cout << "Enter the size of the RAM:";
		cin >> RAM;
		cout << "Number of Computers put in the storage:";
		quantity = intvalidation(0, 10e9);
	}
	void output() {
		Computers::output();
		cout << "Graphich Card size:" << Graphichcard << setw(25) << "RAM size:" << RAM << endl << endl;
		cout << "Number of Computers stored:" << quantity << endl;
	}
private:
	double quantity;
	int Graphichcard;
	int RAM;
};

class Laptops : public Computers {
public:
	Laptops();
	void input() {
		Computers::input();
		cout << "Please enter the screen size in cm:";
		Screen_size = doublevalidation(0,10e9);
		cout << "Please enter the endurance of battery in hours:";
		Battery_life = doublevalidation(0,10e9);
		cout << "Please enter the weight of the laptop:";
		weight = doublevalidation(0,10e9);
		cout << "Please enter the number of Laptops:";
		nr_laptops = intvalidation(0,10e9);
	}
	void output() {
		Computers::output();
		cout<<"Screen size:"<< Screen_size <<endl;
		cout<<"Battery Endurance<<"<< Battery_life <<endl;
		cout<<"Weight of the laptop"<< weight <<endl;
		cout<<"Number of laptops stored:"<< nr_laptops <<endl;
	}
private:
	int Screen_size;
	int Battery_life;
	double weight;
	double nr_laptops;
};

class Gadgets : public Item {
public:
	Gadgets();
	void input() {
		cout << "Type:";
		getline(cin, title);
		cout << "Price:";
		price = doublevalidation(0,10e9);
		cout << "Discount as a percentage:";
		discount = doublevalidation(0,100);
		cout << "Units in stock:";
		units = intvalidation(0,INT_MAX);
		cout << "Location:";
		getline(cin, location);
		cout << "Category:";
		getline(cin, category);
	}
	void output() {
		cout << fixed << endl;
		cout << "Type:" << title << setw(10) << setw(15) << "Category:" << category << setw(20) << "Item location:" << location << endl;
		cout << "Price without discount:" << setprecision(2) << price << "$" << setw(25) << "Price with discount:" << price*(100-discount)/100 << "$" << endl;
		cout << "Units in stock:" << units << endl << endl;
	}
private:
	string title;
	double discount;
	string category;
};

...

Code:

void choice_i_fbo() {
	int inputmenu;
	Item *a;
	cout << "Press 1 to input desktops data\n"
			"Press 2 to input laptops data\n"
			"Press 3 to input devices data\n"
			"Press 0 to return to the main menu\n"
			"Your option:";
	inputmenu = Item::intvalidation(0,3);
	switch(inputmenu) 	{
		case 0: break;
		case 1:
			a=new Desktops;
			v_desktops.push_back(a);
			v_desktops[v_desktops.size()-1]->input();
			break;
		case 2:
			a=new Laptops;
			v_laptops.push_back(a);
			v_laptops[v_laptops.size()-1]->input();
			break;
		case 3:
			a=new Gadgets;
			v_devices.push_back(a);
			v_devices[v_devices.size()-1]->input();
			break;
	}
}

Хееееееееелп! =)

 

У тебя конструктор класса Laptops объявлен, но не определен. В программе не разбирался, либо убери объявление, либо доопредели его код.

 

Спасибо =)