这使我觉得我没有正确使用指针。
main.cpp
#include <iostream>
#include "room.h"
void initializeRooms(std::vector<Room*>& rooms);
int main() {
std::vector<Room*> rooms;
initializeRooms(rooms);
Room* r = rooms[0];
std::cout << "You are in room " << r->getName() << "\n";
return 0;
}
void initializeRooms(std::vector<Room*>& rooms) {
Room roomOne {"roomOne"};
Room roomTwo {"roomTwo"};
Exit exit { &roomOne, &roomTwo };
roomOne.addExit(&exit);
rooms.push_back(&roomOne);
rooms.push_back(&roomTwo);
}
exit.cpp
class Room;
struct Exit {
Room* room_one;
Room* room_two;
};
室
#ifndef ROOM_H
#define ROOM_H
#include <string>
#include <vector>
#include "exit.cpp"
class Room {
private:
std::string name;
std::vector<Exit*> exits;
public:
Room(std::string n): name{n} {
}
void addExit(Exit* e);
std::string& getName();
};
#endif
room.cpp
#include "room.h"
void Room::addExit(Exit* e) {
exits.push_back(e);
}
std::string& Room::getName() {
return name;
}
因此,在主文件中,当调用cout时,我只看到运行编译文件时不断输出空行。现在保持简单并在clang中使用makefile
all: build
build: main.o exit.o room.o
clang++ -std=c++11 main.o exit.o room.o -o simplegame
main.o: main.cpp
clang++ -std=c++11 -c main.cpp
exit.o: exit.cpp
clang++ -std=c++11 -c exit.cpp
room.o: room.cpp
clang++ -std=c++11 -c room.cpp
clean:
rm -rf *o simplegame
最佳答案
抛开除非您完全了解自己在做什么,否则不应该使用原始指针,以下代码有问题:
void initializeRooms(std::vector<Room*>& rooms) {
Room roomOne {"roomOne"}; // this is local object
Room roomTwo {"roomTwo"}; // this is local object as well
Exit exit { &roomOne, &roomTwo }; // exit is also local object and now it holds pointers to other 2 local objects
roomOne.addExit(&exit); // same stuff as before
rooms.push_back(&roomOne); // now you are inserting pointer to local object into vector
rooms.push_back(&roomTwo); // doing that again
} // now all local objects to this function automatically destroyed and you hold pointers to garbage in rooms
因此,无需使用本地对象,而需要在堆上创建它们。
正如我之前所说,我还建议使用shared_ptr和weak_ptr(以后是必需的,因为您有循环引用)。
关于c++ - 从指针检索字符串时获得恒定的空行输出,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/19013591/