如何将不同的模板类型放入一个向量 [英] How to put different template types into one vector

问题描述

我想构造一个具有未知长度或参数数量的消息。我使用了一个简单的模板，如

I'd like to construct a message with unknown length or number of arguments. I took a simple template like

template <typename T> class Argument {
public:
	int size;
	int type;
	T data;
};

和一些重载的

addMessage (int value) {
    Argument<int> *a = new Argument<int>;
    vec.push_back(a);
}

（同样的字符串等）向量。我尝试了

(same for string and so on) I try to push it all into one vector. I tried

std::vector<Argument* > vec;
std::vector<Argument<typename T>* > vec;
std::vector<Argument<>* > vec;

但似乎没有任何效果。有办法做到这一点吗？提前感谢。

but nothing of this seems to work. Is there a way to do this? Thanks in advance.

推荐答案

选项1：确保所有不同类型的参数都派生自基类并使用指针类。注意，这个选项在内存管理方面是有风险的。你可能想通过使用boost :: shared_ptr而不是指针来使它更安全。

Option 1 : make sure that all different types of arguments derive from a base class and use pointers to that class. Note that this option is risky in terms of memory management. You might want to make it safer by using boost::shared_ptr instead of pointers. Otherwise, you must manually clean up when an item is being removed from the vector.

选项2（我个人最喜欢的）：use Boost.Variant 创建所有可能的参数类型的typedef，并将该typedef用作参数类型std :: vector

Option 2 (my personal favorite) : use Boost.Variant to make a typedef of all possible argument types and use that typedef as the argument type in std::vector

typedef boost::variant<ArgumentType1, ArgumentType2, ArgumentType3> ArgumentType;
std::vector<ArgumentType> vec;

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