c ++：可以向量< Base>包含Derived类型的对象？ [英] c++: can vector<Base> contain objects of type Derived?

问题描述

标题几乎说这一切。基本上，这样做是合法的：

  class Base {
 // stuff 
} 
 
 class Derived：public Base {
 // more stuff 
} 
 
 vector< Base> foo; 
派生吧; 
 foo.push_back（bar）; 
  

根据我看到的其他帖子，以下是好的，但我不想在这种情况下使用指针，因为它很难让它线程安全。

  vector< Base *> foo; 
 Derived * bar = new Derived; 
 foo.push_back（bar）; 
   
不， Derived 对象将 切片 ：所有其他成员都将被丢弃。
 
 
 
而不是原始指针，使用 std :: vector< std :: unique_ptr& > 。
 
The title pretty much says it all. Basically, is it legal to do this:
class Base {
    //stuff
}

class Derived: public Base {
    //more stuff
}

vector<Base> foo;
Derived bar;
foo.push_back(bar);
Based on other posts I've seen, the following is okay, but I don't want to use pointers in this case because it's harder to make it thread safe.
vector<Base*> foo;
Derived* bar = new Derived;
foo.push_back(bar);

解决方案
No, the Derived objects will be sliced: all additional members will be discarded.

Instead of raw pointers, use std::vector<std::unique_ptr<Base> >.

                        
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