Clang VS VC++:“error: declaration of 'T' shadows template parameter”

Question

I was trying to compile the following code for the classic copy&swap idiom on my Mac with clang 3.3

template class node{

private:
             


        

Answer 1

I believe that this is what you want (which happens to be what you just added to your question as the third option)

#include <utility>

template <typename T> class node;
template <typename T> void swap(node<T> & a, node<T> & b);

template<typename T> class node {
    private:
        node<T>* left;
        node<T>* right;
        T value;

    public:
        friend void swap<>(node<T>&, node<T>&);
};

template <typename T> void swap(node<T> & a, node<T> & b) {
    std::swap(a.left, b.left);
    std::swap(a.right, b.right);
    std::swap(a.value, b.value);
}

int main() {
    node<int> x, y;
    swap(x, y);
}