你如何将结构模板标记为朋友?

我有这样的代码:

template <typename T, typename U> struct MyStruct {
    T aType;
    U anotherType;
};

class IWantToBeFriendsWithMyStruct
{
    friend struct MyStruct; //what is the correct syntax here ?
};

为模板赋予友谊的正确语法是什么?

class IWantToBeFriendsWithMyStruct
{
    template <typename T, typename U>
    friend struct MyStruct;
};