Go generics may use square brackets [] not parenthesis ()(groups.google.com)

  List<X> foo(List<'X> inp) =
    ...
    List<X> bar(List<'X> xs) = ... # new X scoped to this declaration
    List<X> baz(List<X> xs) = ... # use foo's X
    ...

    T swap<T>(T* left, T* right) {
        T temp = left;
        *left = *right;
        *right = temp;
    }

    ...

    int a = 1, b = 2;
    char c = 'c', d = 'd';

    swap<int>(&a, &b);
    swap<char>(&c, &d);

    #declare_swap_function(T) T swap_ ## T(T* left, T* right) {\
        T temp = left;\
        *left = *right;\
        *right = temp;\
    }

    ...

    declare_swap_function(int);
    declare_swap_function(char);

    ...

    int a = 1, b = 2;
    char c = 'c', d = 'd';

    swap_int(&a, &b);
    swap_char(&c, &d);