铸造容器C ++ [英] Casting containers C++

问题描述

可能重复:
是否可以将基本类型的STL容器转换为派生类型?

Possible Duplicate:
Is it ok to cast a STL container with Base type to Derived type?

这应该是一个快速的问题...如果我有一个基类的容器，例如STL列表，是否可以将整个容器转换为子类类型?例如

This should be a quick question... If I have a container, say an STL list, of a base class, is it possible to casts the entire container to a type of subclass? E.g.

[A inherits from base class B]

list<B*> list1;
list1.push_back(new A());

list<A*> list2 = list1;

编译器在抱怨:"conversion from std::vector<B*, std:allocator<B*> >' to non-scalar type 'std::vector<Bar*, ...>' requested."

这是可能的，还是我只是搞砸了?

Is this possible, or am I'm just screwing it up?

推荐答案

否.如果std::is_same<T,U>::value是false，即T和U的类型参数不同，则std::list<T>和std::list<U>是完全不兼容的类型.

No. std::list<T> and std::list<U> are completely different, incompatible types, if std::is_same<T,U>::value is false, i.e if the type arguments T and U aren't same.

使用std::transform并在回调中进行适当的转换.

Use std::transform and do appropriate casting in the callback.

这篇关于铸造容器C ++的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！