问题描述
#include <iostream>
#include <memory>
#include <algorithm>
class A {
public:
A(){
std::cout << "default ctor for A" << std::endl;
}
~A(){
std::cout << "default dtor for A" << std::endl;
}
};
class B : A{
B(){
std::cout << "default ctor for B" << std::endl;
}
~B(){
std::cout << "default dtor for B" << std::endl;
}
};
int main()
{
auto ap = std::shared_ptr<A>(new B());
return 0;
}
我收到错误
No matching conversion for functional-style cast from 'B *' to 'std::shared_ptr<A>'
在这一行 自动 ap = std::shared_ptr(new B());
我在这里做错了什么?
解决方法
B 类应该声明为
class B : public A{
public:
B(){
std::cout << "default ctor for B" << std::endl;
}
~B(){
std::cout << "default dtor for B" << std::endl;
}
};