home | help 
std::forward_list::resize(3)   C++ Standard Libary  std::forward_list::resize(3)

NAME
     std::forward_list::resize - std::forward_list::resize

Synopsis
	void  resize(  size_type  count  );			      (1) (since
     C++11)
	void resize( size_type count, const  value_type&  value  );  (2)  (since
     C++11)

	Resizes  the  container to contain count elements, does nothing if count
     ==
	std::distance(begin(), end()) (i.e. if count is  equal	to  the  current
     size).

	If  the  current size is greater than count, the container is reduced to
     its first
	count elements.

	If the current size is less than count,

	1) additional default-inserted elements are appended.
	2) additional copies of value are appended.

Parameters
	count	       -	  new size of the container
	value	       -	  the value to initialize the new elements with

Type requirements
	-
	T must meet the requirements of DefaultInsertable in order to use  over-
     load (1).
	-
	T  must meet the requirements of CopyInsertable in order to use overload
     (2).

Return value
	(none)

Complexity
	Linear in the difference between the current size and count.  Additional
     complexity
	possible  due  to list traversal to reach the first element to erase/the
     end position
	to insert.

Notes
	If value-initialization in overload (1) is undesirable, for example,  if
     the elements
	are  of  non-class type and zeroing out is not needed, it can be avoided
     by providing
	a custom Allocator::construct.

Example
     // Run this code

      #include <forward_list>
      #include <iostream>

      void print(auto rem, const std::forward_list<int>& c)
      {
	  for (std::cout << rem; const int el : c)
	      std::cout << el << ' ';
	  std::cout << '\n';
      }

      int main()
      {
	  std::forward_list<int> c = {1, 2, 3};
	  print("The forward_list holds: ", c);

	  c.resize(5);
	  print("After resize up to 5: ", c);

	  c.resize(2);
	  print("After resize down to 2: ", c);

	  c.resize(6, 4);
	  print("After resize up to 6 (initializer = 4): ", c);
      }

Output:
      The forward_list holds: 1 2 3
      After resize up to 5: 1 2 3 0 0
      After resize down to 2: 1 2
      After resize up to 6 (initializer = 4): 1 2 4 4 4 4

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

http://cppreference.com 	   2024.06.10	    std::forward_list::resize(3)
home | help