template function for complex types - c++

Question

Is there any way in C++17 or older to use single template implementation of function compute in the code below?
template <typename T>
class C
{
public:
T x, y;
C() = default;
C(T x, T y) : x(x), y(y) {}
operator T() const { return x; }
C operator +(const C<T> &c) const { return C(x + c.x, y + c.y); }
C operator +(const T &t) const { return C(x + t, y); }
};
template <typename T>
void compute(C<T> *a, T *b, size_t size)
{
while (size--)
a[size] = a[size] + b[size];
}
template <typename T>
void compute(T *a, C<T> *b, size_t size)
{
while (size--)
a[size] = a[size] + b[size];
}
template <typename T>
void compute(C<T> *a, C<T> *b, size_t size)
{
while (size--)
a[size] = a[size] + b[size];
}
int main()
{
const size_t size = 4;
C<float> a[size];
float b[size];
compute(a, b, size);
compute(b, a, size);
compute(a, a, size);
}

Answer 1

Yes, if you are willing to tolerate a little boilerplate (I imagine you have many, many functions just like compute).
template <typename A, typename B>
struct is_cable_t : std::false_type {};
template <typename A>
struct is_cable_t<A, C<A>> : std::true_type {};
template <typename A>
struct is_cable_t<C<A>, A> : std::true_type {};
template <typename A>
struct is_cable_t<C<A>, C<A>> : std::true_type {};
template <typename A, typename B>
constexpr bool is_cable_v = is_cable_t<A,B>::value;
template <typename K, typename S,
typename R = typename std::enable_if<is_cable_v<K,S>>::type>
void compute(K *a, S *b, size_t size)
{
while (size--)
a[size] = a[size] + b[size];
}