std::make_optional
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <optional> | ||
| template< class T >  constexpr std::optional<std::decay_t<T>> make_optional( T&& value ); | (1) | (since C++17) | 
| template< class T, class... Args >  constexpr std::optional<T> make_optional( Args&&... args ); | (2) | (since C++17) | 
| template< class T, class U, class... Args >  constexpr std::optional<T> make_optional( std::initializer_list<U> il, Args&&... args ); | (3) | (since C++17) | 
1) Creates an optional object from 
value. Effectively calls std::optional<std::decay_t<T>>(std::forward<T>(value))2) Creates an optional object constructed in-place from 
args.... Equivalent to return std::optional<T>(std::in_place, std::forward<Args>(args)...);.3) Creates an optional object constructed in-place from 
il and args.... Equivalent to return std::optional<T>(std::in_place, il, std::forward<Args>(args)...);.| Contents | 
[edit] Parameters
| value | - | the value to construct optional object with | 
| il, args | - | arguments to be passed to the constructor of T. | 
[edit] Return value
The constructed optional object.
[edit] Exceptions
Throws any exception thrown by the constructor of T.
[edit] Notes
T need not be movable for overloads (2-3) due to guaranteed copy elision.
[edit] See also
| constructs the optional object (public member function) | 


