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std::forwar...place_after(3)   C++ Standard Libary  std::forwar...place_after(3)

NAME
     std::forward_list::emplace_after - std::forward_list::emplace_after

Synopsis
	template<  class...  Args  >					  (since
     C++11)
	iterator emplace_after( const_iterator pos, Args&&... args );

	Inserts a new element into a position after the  specified  position  in
     the container.
	The element is constructed in-place, i.e. no copy or move operations are
     performed.
	The  constructor  of  the  element is called with exactly the same argu-
     ments, as
	supplied to the function.

	No iterators or references are invalidated.

Parameters
	pos  - iterator after which the new element will be constructed
	args - arguments to forward to the constructor of the element

Return value
	Iterator to the new element.

Complexity
	Constant.

Exceptions
	If an exception is thrown for any reason, this function  has  no  effect
     (strong
	exception safety guarantee).

Example
	The  example demonstrates a canonical filling of a single-linked list in
     natural (as
	opposed to reverse) order.

     // Run this code

      #include <forward_list>
      #include <iostream>
      #include <string>

      struct Sum
      {
	  std::string remark;
	  int sum;

	  Sum(std::string remark, int sum)
	      : remark{std::move(remark)}, sum{sum} {}

	  void print() const
	  {
	      std::cout << remark << " = " << sum << '\n';
	  }
      };

      int main()
      {
	  std::forward_list<Sum> list;

	  auto iter = list.before_begin();
	  std::string str{"1"};

	  for (int i{1}, sum{1}; i != 10; sum += i)
	  {
	      iter = list.emplace_after(iter, str, sum);
	      ++i;
	      str += " + " + std::to_string(i);
	  }

	  for (const Sum& s : list)
	      s.print();
      }

Output:
      1 = 1
      1 + 2 = 3
      1 + 2 + 3 = 6
      1 + 2 + 3 + 4 = 10
      1 + 2 + 3 + 4 + 5 = 15
      1 + 2 + 3 + 4 + 5 + 6 = 21
      1 + 2 + 3 + 4 + 5 + 6 + 7 = 28
      1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36
      1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45

See also
	insert_after inserts elements after an element
		     (public member function)

http://cppreference.com 	   2024.06.10	    std::forwar...place_after(3)
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