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#include <memory>
 
template<typename T>
struct Helper
{
	template<template<typename...> class Wrapper = std::unique_ptr, typename... Args>
	static Wrapper<T, Args...> Wrap(T const &t)
	{
		return Wrapper<T, Args...>{new T{t}};
	}
};
 
template<typename T, template<typename...> typename Wrapper = std::unique_ptr, typename... Args>
struct WrapperHelper final
{
};
 
int main()
{
	int x = 0;
	auto c1 = Helper<int>::Wrap<>(x);
	auto c2 = Helper<int>::Wrap<std::shared_ptr>(x);
	auto c3 = Helper<int>::Wrap<WrapperHelper, int>(*c1);
}
 

prog.cpp: In function 'int main()':
prog.cpp:22:48: error: no matching function for call to 'Helper<int>::Wrap(int&)'
  auto c2 = Helper<int>::Wrap<std::shared_ptr>(x);
                                                ^
prog.cpp:7:29: note: candidate: template<template<class ...> class typedef Wrapper Wrapper, class ... Args> static Wrapper<T, Args ...> Helper<T>::Wrap(const T&) [with Wrapper = Wrapper; Args = {Args ...}; T = int]
  static Wrapper<T, Args...> Wrap(T const &t)
                             ^
prog.cpp:7:29: note:   template argument deduction/substitution failed:
prog.cpp: In substitution of 'template<template<class ...> class typedef Wrapper Wrapper, class ... Args> static Wrapper<T, Args ...> Helper<T>::Wrap(const T&) [with typedef Wrapper Wrapper = std::shared_ptr; Args = {}]':
prog.cpp:22:48:   required from here
prog.cpp:7:29: error: wrong number of template arguments (2, should be 1)
In file included from /usr/include/c++/5/bits/shared_ptr.h:52:0,
                 from /usr/include/c++/5/memory:82,
                 from prog.cpp:1:
/usr/include/c++/5/bits/shared_ptr_base.h:345:11: note: provided for 'template<class _Tp> class std::shared_ptr'
     class shared_ptr;
           ^
prog.cpp:23:53: error: no matching function for call to 'Helper<int>::Wrap(int&)'
  auto c3 = Helper<int>::Wrap<WrapperHelper, int>(*c1);
                                                     ^
prog.cpp:7:29: note: candidate: template<template<class ...> class typedef Wrapper Wrapper, class ... Args> static Wrapper<T, Args ...> Helper<T>::Wrap(const T&) [with Wrapper = Wrapper; Args = {Args ...}; T = int]
  static Wrapper<T, Args...> Wrap(T const &t)
                             ^
prog.cpp:7:29: note:   template argument deduction/substitution failed:

Standard output is empty