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c++templates

Specialize Class for all other types

Assume having MyContainer template class, like:

template <typename T>
class MyContainer {
public:
    T *content;
    void *data;
};

Now, assume having MyContetWithData class as well, which already contains the void *data field, hence there is no need to duplicate it in MyContainer, but, all other types yet need said field, only MyContetWithData does not need it.

How can we specialize MyContainer so that void *data; is removed from MyContainer if T is of type MyContetWithData, but keep said field for all other types?

Solution

  • You can simply provide an explicit specialization for MyContetWithData as shown below:

    //primary template for all other types as before
template <typename T>
class MyContainer {
public:
    T *content;
    void *data;
};
//explicit specialization for MyContetWithData without data
template <> class MyContainer<MyContetWithData> 
{ 
    MyContetWithData *content;
};

    Demo