error: No matching function for call to class object - c++

Question

Each time I've attempted to build my project, I receive the same error:
>error: no matching function for call to 'Agent::Agent()'
>note: candidates are: Agent::Agent(std::string, room*)
>note: Agent::Agent(const Agent&)
Initially I assumed that I was feeding the wrong values, but even after seemingly correcting, I still get the same error.
main
#include <iostream>
#include <string>
#include <sstream>
#include "room.h"
#include "Thing.h"
//#include "Agent.h"
//#include "Grue.h"
//#include "Player.h"
using namespace std;
int main()
{
srand(time(NULL));
room *entrance = new room("Entrance","A wide open entrance...", 100);
room *hallway = new room("Hallway","A long hallway...", 50);
room *ballroom = new room("Ballroom","A huge ballroom...", 200);
room *garden = new room("Garden","A lush garden...", 150);
entrance->link("south", hallway);
hallway->link("north", entrance);
hallway->link("east", ballroom);
ballroom->link("west", hallway);
ballroom->link("east", garden);
hallway->printLinked();
while(true)
{
for(int i = 0; i < agents.size(); i++)
{
bool ok = agents[i]->act();
if(!ok)
{
cout << "Game quits." << endl;
return 0;
}
}
}
Player *josh = new Player("Josh", entrance);
Player *tracy = new Player("Tracy", entrance);
game.addAgent(josh);
game.addAgent(tracy);
cout << "Welcome!" << endl;
// the step() function in the Game class will eventually
// return false, when a player chooses to quit;
// this tiny "while" loop keeps asking the game.step()
// function if it is false or true; the effect is
// that the step() function is called repeatedly
// until it returns false
while(game.step());
return 0;
}
Thing header
#ifndef THING_H
#define THING_H
#include <iostream>
#include <string>
#include "room.h"
class room;
class Thing
{
private:
std::string name, desc;
protected:
room* cur_room;
public:
Thing(std::string _name, std::string _desc);
std::string getName();
std::string getDesc();
int getSize();
};
#endif // THING_H
Thing cpp
#include "Thing.h"
Thing::Thing(std::string _name, std::string _desc)
{
name = _name;
desc = _desc;
cur_room = NULL;
}
std::string Thing::getName()
{
return name;
}
std::string Thing::getDesc()
{
return desc;
}
int Thing::getSize()
{
return size;
}
Agent header
#ifndef AGENT_H
#define AGENT_H
#include "Thing.h"
#include <iostream>
#include <string>
#include "room.h"
class Agent : public Thing
{
protected:
//bool walk(std::string exit);
room *cur_room;
std::string name;
public:
Agent(std::string _name, room *_cur_room);
void get_curroom();
virtual bool act() = 0;
std::string getName() { return name; }
};
#endif // AGENT_H
Agent cpp
#include "Agent.h"
Agent::Agent(std::string _name, room *_cur_room)
{
name = _name;
room = _cur_room;
}
bool Agent::walk(std::string exit)
{
return 0;
}
bool Agent::act()
{
return 0;
}
void Agent::get_curroom()
{
return cur_room;
}
Player header
#ifndef PLAYER_H
#define PLAYER_H
#include <iostream>
#include <string>
#include "Agent.h"
#include "room.h"
class room;
class Player : public Agent
{
private:
std::string name;
protected:
public:
Player(std::string _name, room *starting_room);
bool Act();
};
#endif // PLAYER_H
Player cpp
#include "Player.h"
Player::Player(std::string _name, room *starting_room)
{
name = _name;
cur_room = starting_room;
}
bool Player::Act()
{
std::cout << "Where do you want to go? (or 'quit')" << std::endl;
}
I'm honestly stumped on where to go next. Any help is greatly appreciated!

Answer 1

In your inheritance chain of Player<-Agent<-Thing, you aren't passing the constructor parameters up to the parent. So, you need to change the Player constructor to:
Player::Player(std::string _name, room *starting_room)
:Agent(_name, starting_room)
{
name = _name;
cur_room = starting_room;
}
And you need to change the Agent constructor to:
Agent::Agent(std::string _name, room *_cur_room)
:Thing(_name, "")
{
name = _name;
room = _cur_room;
}
The parts I added after the colons are called initialization lists. One use of these is to call the constructor of the parent class. In C++, you have to call the parent class's constructor by name, since there is no keyword to reference the parent class generally.

Answer 2

The problem is that in the constructor of Player you don't call the constructor of the base class Agent and the latter doesn't have the default constructor. To fix it call the Agent's constructor (or add the default constructor):
Player::Player(std::string _name, room *starting_room)
: Agent(_name, starting_room)
{
// ...
}