Is it possible to use 'enable_if' and 'is_same' with variadic function templates?

Question

These two non-variadic function templates do compile:

template 
typename std::enable_if::value, v         


        

Answer 1

Yes. You can use a fold expression in C++17:

template 
typename std::enable_if<(std::is_same::value && ...), void>::
type testFunction(T a, U... bs) {
    std::cout << "bs are floats\n";
}

In C++11, you can reimplement std::conjunction:

template struct conjunction : std::true_type { };
template struct conjunction : B1 { };
template
struct conjunction 
    : std::conditional_t, B1> {};

template 
typename std::enable_if<
    std::conjunction_v...>, 
    void
>::type testFunction(T a, U... bs) {
    std::cout << "bs are floats\n";
}