关于c ++：将派生类转换为具有相同公共函数的泛型类类型，同时仍然能够调用派生类的函数

Convert derived class to generic class type with the same public functions, while still being able to call the function of the derived class

在以后的程序中，我有一个类动物，它派生出具有相同公共功能但不同私人功能的类猫和狗。我想让用户在运行时决定要创建哪个动物。我做了一个简单的例子，说明我大概想要什么，但显然不起作用。我不知道怎么解决这个问题，希望得到你的帮助。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52

#include <cstdio>

class canimal
{
public:
int sound()
{
std::printf("...
");
return 0;
}
};

class cdog : public canimal
{
public:
int sound()
{
std::printf("Woof!
");
return 0;
}
};

class ccat : public canimal
{
public:
int sound()
{
std::printf("Mieau!
");
return 0;
}
};

int main()
{
canimal *animal;
cdog *dog;

// I would like to let the user decide here which animal will be made
// In this case, I would like the function to say"Woof!", but of course it doesn't...
animal = new cdog;
animal->sound();

// Here it works, but I would like the pointer to be of the generic class
// such that the type of animal can be chosen at runtime
dog = new cdog;
dog->sound();

return 0;
}