template<typename T>
class Proxy : public std::unique_ptr<T>
{
public:

// Note: both cases are compiling

#if 1
	// Wrong, suggestion (see below) -> compilation error after applying fix
	using BaseClass = std::unique_ptr<T>; // typedef
 	using BaseClass::unique_ptr; // using unique_ptr constructor
#else
	// OK, no suggestion
	using std::unique_ptr<T>::unique_ptr; // using unique_ptr constructor
#endif
};


class MyClass
{
public:
	MyClass();

private:
	class MyClassImpl;
	Proxy<MyClassImpl> m_Impl;
};

class MyClass::MyClassImpl { };

MyClass::MyClass()
	: m_Impl(new MyClassImpl())
{} // Suggestion here (when #if 1): "Default constructor body can be replaced with '= default'
// This suggestion shouldn't happen at all in any cases

/*
// Replaced by:

MyClass::MyClass()
	: m_Impl(new MyClassImpl())
= default; // Compilation error: expecting {}

*/

class HtmlTag
{
public:

	HtmlTag(const std::string& iTagName) {}
};

class Head : public HtmlTag
{
public:

	Head()
		: HtmlTag("head")
	{} // Suggest to replace the body by '=default', only if the code is in a header file
};

using BaseClass::BaseClass;

using std::unique_ptr<T>::std::unique_ptr<T>