Question

In a C++ template with the generic type T, I can use

const T &

to get a reference to a constant T. However, if now T itself is a reference type (like e.g. T = int &), the above term resolves to

int &

and not to

const int &

which quite makes sense, since any reference itself is always constant. However, is there still a way to require a

const T &

if T itself is a reference type?

Edit: sample code to evaluate (g++ compiler):

template <typename T> class TemplateClass
{
public:
    void foo(const T &bar) { }
};

int main()
{
    TemplateClass<int &> x;
    x.foo(0);   // <-- compile error: no conversion from int to int&
    return 0;
}

Answer 1

Remove the reference:

template<typename T>
void Test(const typename std::remove_reference<T>::type & param)
{
        param = 20;
}

Now it works as expected.