C++ 等效于 Java 的链表/C# 的数组列表？

Question

Is there an STL container or something else that gives the same functionality as Java's Linked List or C#'s Array List? ie appending different types into the same array like

List.Append(1);
List.Append("I am a string");
List.Append(True);

and dynamic functions like

List.Resize();
List.GetSize();

etc.?

If not, can u implement one yourself using templates etc.? If so, How?

Answer 1

It's hard to implement this using templates because templates assume a single type for members. In C++ you'll have to use polymorphism with a common source (which is available in Java and C# as a common "Object" parent for all the classes, IMHO).

You can try to do it using the boost library, and the boost::variant or boost::any ( choose which one fits your needs ).

Answer 2

First off, ArrayList in C# and LinkedList in Java are fundamentally different beasts (one implements a resizable array while the other implements a linked list).

Secondly, ArrayList in C# (but not in Java) is deprecated; use the generic List<T> instead (in your case, a List<object> ).

Thirdly, this corresponds to std::vector in C++.

If you need to insert different types into it, you got three basic choices:

• Use Boost.Any
• Use Boost.Variant
• Use a common base class. This is the most sensible alternative in 95% of the cases.

Answer 3

You could use boost::any and then a std::list.
Take a look at the examples of the boost homepage.

Answer 4

You can combine std::list with boost.Variant as type T.

Answer 5

Java/C# manage this by having an Object class that all classes derive from. C++ does not have this root.

If all your data is in a class hierarchy then you can use a std::list or vector of pointers (bare or smart) to the root class.

If not then you need to use an adaptor to make them appear the same class eg boost::variant and then make a list of those. eg std::list<boost::variant>