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std::make_optional(3)	      C++ Standard Libary	 std::make_optional(3)

NAME
       std::make_optional - std::make_optional

Synopsis
	  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	     >
       (2) (since C++17)
	  constexpr std::optional<T> make_optional( Args&&... args );
	  template< class T, class U, class... Args >
	  constexpr  std::optional<T>  make_optional( std::initializer_list<U>
       (3) (since C++17)
	  il, Args&&...	args );

	  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::for-
       ward<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::for-
       ward<Args>(args)...);.

Parameters
	  value	   - the value to construct optional object with
	  il, args - arguments to be passed to the constructor of T.

Return value
	  The constructed optional object.

Exceptions
	  Throws any exception thrown by the constructor of T.

Notes
	  T need not be	movable	for overloads (2-3)  due  to  guaranteed  copy
       elision.

Example
       // Run this code

	#include <optional>
	#include <iostream>
	#include <iomanip>
	#include <vector>
	#include <string>

	int main()
	{
	    auto op1 = std::make_optional<std::vector<char>>({'a','b','c'});
	    std::cout << "op1: ";
	    for	(char c: op1.value()){
		std::cout << c << ",";
	    }
	    auto op2 = std::make_optional<std::vector<int>>(5, 2);
	    std::cout << "\nop2: ";
	    for	(int i:	*op2){
		std::cout << i << ",";
	    }
	    std::string	str{"hello world"};
	    auto op3 = std::make_optional<std::string>(std::move(str));
	    std::cout  <<  "\nop3: " <<	quoted(op3.value_or("empty value")) <<
       '\n';
	    std::cout << "str: " << std::quoted(str) <<	'\n';
	}

Possible output:
	op1: a,b,c,
	op2: 2,2,2,2,2,
	op3: "hello world"
	str: ""

See also
	  constructor	constructs the optional	object
			(public	member function)

http://cppreference.com		  2022.07.31		 std::make_optional(3)

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