c++ - shared_ptr vector 导致错误 : "no instance of overloaded function" when wanting to push_back vector list

Question

我有一个基类的智能指针来防止这样的对象切片:

vector<shared_ptr<BaseClass>> vectorOfObjects;

我想通过一个函数传递这个对象，然后将派生对象添加到 vector 列表中:

function(vector<shared_ptr<BaseClass>>& vectorOfObjects) {}

在这个函数中，我创建了一个要添加到列表中的新派生对象:

DerivedClass derivedObject = DerivedClass();

vectorOfObjects.push_back(&derivedObject);

我在上面最后一行的点下遇到错误

no instance of overloaded function std::vector<_Ty,_Ax>::pushback
 [with _Ty="std::tr1::shared_ptr<BaseClass>,_Ax=std::allocator<std:
:tr1::shared_ptr<BaseClass>>]" matches the argument list

任何帮助都将不胜感激，因为我似乎无法找到正确的解决方案来通过函数传递由对象指针组成的 vector (需要防止对象切片)。

Answer 1

使用

// DerivedClass derivedObject = DerivedClass(); <<< Not needed
vectorOfObjects.push_back(std::make_shared<DerivedClass>());

有很多 constructor declarations允许从 std::shared_ptr<DerivedClass> 转换至 std::shared_ptr<BaseClass> .

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来自您的 comment

If I need to make a separate declaration, as I also have a vector member in my BaseClass, how can I declare a derivedObject separately as I have attempted earlier?

我不是很清楚 “因为我的 BaseClass 中也有一个 vector 成员” 与它有什么关系，但如果你坚持你可以这样做:

DerivedClass derivedObject* = new DerivedClass();
// Do special stuff only available in DerivedClass
derivedObject->specialFunc();
vectorOfObjects.push_back(std::shared_ptr<DerivedClass>(derivedObject));