Template specialization for union type

Question

How can I specialise template for union types? Suppose I have template function

template <typename T>
void foo(T value);

I want to prohibit calling this function if T is not any union type. How can I achieve this?

Answer 1

I want to prohibit calling this function if T is not any union type. How can I achieve this?

Maybe with std::is_union ?

template <typename T>
std::enable_if_t<std::is_union<T>::value> foo(T value)
 { /* ... */ }