我什么时候应该使用关键字“typename"?使用模板时
我最近一直在做一个小项目,但我想不出什么..
I've been working lately on a small project, and I couldn't figure out something..
我得到了一个包含类的 .h 文件,使用了 typename 模板.在那个班级里面有一个私人班级.
I've been given a .h file that was containing a class, using a typename template. Inside that class there was a private class.
template <typename T>
class Something
{
public:
Something();
~Something();
Node* Function1(int index);
int Index(const T& id);
private:
class Node()
{
public:
T id;
//Imagine the rest for the Node
};
};
当我想定义Something"类的函数时出现问题
The problem occured when I wanted to define the functions of the class "Something"
这是我的做法(在 .inl 文件中)
Here's how I was doing it (in a .inl file)
template<typename T>
Node* Something::Function1(int index) //Is the return type well written?
{
// returns the node at the specified index
}
template<typename T>
int Something::Index(const T& id) //Is the parameter type well specified?
{
// returns the index of the node with the specified id
}
所以问题部分是在定义部分......我是否必须告诉编译器返回类型(在这种情况下 Node*)使用 typename 模板(像这样:typename Node*
) ?那么参数呢?typename const Node&
?
So the bugging part was in the definitions part... Do I have to tell the compiler that the return type (in this case Node*) uses the typename template (like this: typename Node*
) ? And what about the parameter ? typename const Node&
?
所以基本上,我什么时候必须指定函数/参数是否使用模板?
So basically, when do I have to specify wether the function/parameter uses a template?
感谢您的时间.
推荐答案
template<typename T>
typename Something<T>::Node * Something::Function1(int index) //Is the return type well written?
{
// returns the node at the specified index
}
相关文章