STL容器作为模板参数 [英] STL container as a template parameter

问题描述

我正在尝试将STL容器作为模板参数传递.在这种情况下，就是向量.

I'm trying to pass an STL container as a template parameter. In this case, the vector.

这是我无法运行的代码:

Here is my not-functional code:

template<template<class> class TContainer, class TObject>
class Foobar
{
public:

    explicit Foobar( TContainer<TObject*> & container )
    :
    container_( container ){}


private:

    TContainer<TObject*> & container_;
};


int _tmain(int argc, _TCHAR* argv[])
{
    std::vector<IUnknown*> v;

    Foobar<std::vector, IUnknown*> bla( v );

    return 0;
}

这是我要执行的所有操作，因为编译器无法吞并此内容吗?

Is this, what I'm trying to do possible at all, because the compiler cannot swallow this?

推荐答案

您的代码有几处错误，这是一个有效的示例:

There are several things wrong with your code, here is a working example:

template<template<class, class> class TContainer, class TObject>
class Foobar
{
public:
    explicit Foobar( TContainer<TObject*, std::allocator<TObject*>> & container )
    :
    container_( container ){}

private:
    TContainer<TObject*, std::allocator<TObject*>> & container_;
};

int main()
{
    std::vector<IUnknown*> v;
    Foobar<std::vector, IUnknown> bla( v );
}

您的代码的主要缺陷是 std :: vector 带有两个模板参数.看起来像这个 template< class T，class Allocator = std :: allocator< T>类向量； .另外， Joachim Pileborg 对于双指针问题 IUnknown ** 是正确的.但是，您可以使用以下代码简化代码:

The main fault of your codes it that std::vector takes two template arguments. It looks like this template<class T, class Allocator = std::allocator<T>> class vector;. Also, Joachim Pileborg is right about the double pointer issue, IUnknown**. However, you could simplify your code with the following:

template<class TContainer>
class Foobar
{
public:
    explicit Foobar( TContainer & container )
    :
    container_( container ){}

private:
    TContainer & container_; // Be careful with reference members
};

int main()
{
    std::vector<IUnknown*> v;
    Foobar<std::vector<IUnknown*>> bla( v ); // C++11 decltype(v) could be used
}

这篇关于STL容器作为模板参数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！