小编ler*_*ray的帖子

可能重复:
GCC链接器找不到标准库？

我试图搞砸我在假期里得到的这本C++书,我来自对python的有限理解,所以这些东西对我来说真的很奇怪.

我从第一课中输入了这段代码到我的文本编辑器中并将其保存为.cpp文件.

#include <iostream>
int main()
{
    std::cout << "Enter two numbers:" << std::endl;
    int v1 = 0, v2 = 0;
    std::cin >> v1 >> v2;
    std::cout << "The sum of " << v1 << " and " << v2
              << " is " << v1 + v2 << std::endl;
    return 0;
}

但是当我尝试编译它时,我的终端给出了这个疯狂的输出,是怎么回事？

Raymond-Weisss-MacBook-Pro:c++ Raylug$ gcc prog2.cpp
Undefined symbols for architecture x86_64:
  "std::basic_istream<char, std::char_traits<char> >::operator>>(int&)", referenced from:
      _main in cckdLEun.o
  "std::basic_ostream<char, std::char_traits<char> >::operator<<(std::basic_ostream<char, std::char_traits<char> >& (*)(std::basic_ostream<char, std::char_traits<char> …

我在理解类中的继承方面遇到了一些麻烦,并想知道为什么这些python代码不起作用,有没有人可以告诉我这里出了什么问题？

## Animal is-a object 
class Animal(object):
    def __init__(self, name, sound):
        self.implimented = False
        self.name = name
        self.sound = sound

    def speak(self):
        if self.implimented == True:
            print "Sound: ", self.sound

    def animal_name(self):
        if self.implimented == True:
            print "Name: ", self.name



## Dog is-a Animal
class Dog(Animal):

    def __init__(self):
        self.implimented = True
        name = "Dog"
        sound = "Woof"

mark = Dog(Animal)

mark.animal_name()
mark.speak()

这是通过终端的输出

Traceback (most recent call last):
  File "/private/var/folders/nd/4r8kqczj19j1yk8n59f1pmp80000gn/T/Cleanup At Startup/ex41-376235301.968.py", line 26, in <module>
    mark = Dog(Animal)
TypeError: …

我目前正在通过 roguelike 教程自学 Rust，并且我正在尝试按下按键以对角移动角色，这意味着player_x -=1,player_y -= 1向左。

无论我尝试以哪种方式排列代码，我都会不断收到来自编译器的错误消息。我在文档或 GitHub 上的任何地方都找不到任何示例。

Key { code: Escape, .. } => return true, // exit game

// movement keys
Key { code: Up, .. } => *player_y -= 1,
Key { code: Down, .. } => *player_y += 1,
Key { code: Left, .. } => *player_x -= 1,
Key { code: Right, .. } => *player_x += 1,
Key { printable: 'k', .. } => *player_y -= 1,
Key …