std::default_delete::default_delete
From cppreference.com
                    
                                        
                    < cpp | memory | default delete
                    
                                                            
                    | constexpr default_delete = default; | (1) | (since C++11) | 
| template <class U> default_delete( const default_delete<U>& d ); | (2) | (since C++11) | 
1) Constructs a 
std::default_delete object.
2) Constructs a 
std::default_delete object from another std::default_delete object.  This constructor will only participate in overload resolution if U* is implicitly convertible to T*.[edit] Parameters
| d | - | a deleter to copy from | 
[edit] Exceptions
[edit] Example
| This section is incomplete Reason: no example |