I was thinking of a class like:

```
template < typename ...Whatever >
class MyClass
{
public:
    static constexpr bool has_default_ctr = Something;

    // I want this only if "has_default_ctr" is "true".
    MyClass();

    //...
};

```

I don't think I can use a constructor template and `std::enable_if` for this (because there's no arguments). Am I wrong? If not, is there some other way to do this?