public member function

std::forward_list::cbefore_begin

<forward_list>
const_iterator cbefore_begin() const noexcept;
Return const_iterator to before beginning
Returns a const_iterator pointing to the position before the first element in the container.

A const_iterator is an iterator that points to const content. This iterator can be increased and decreased (unless it is itself also const), just like the iterator returned by forward_list::before_begin, but it cannot be used to modify the contents it points to.

The value returned shall not be dereferenced.

Parameters

none

Return Value

A const_iterator to the position before the beginning of the sequence.

Member type const_iterator is a forward iterator type.

Example

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// forward_list::cbefore_begin
#include <iostream>
#include <forward_list>

int main ()
{
  std::forward_list<int> mylist = {77, 2, 16};

  mylist.insert_after ( mylist.cbefore_begin(), 19 );

  std::cout << "mylist contains:";
  for ( int& x: mylist ) std::cout << " " << x;
  std::cout << std::endl;

  return 0;
}


Output:
mylist contains: 19 77 2 16

Complexity

Constant.

Iterator validity

No changes.

See also