public member type
<forward_list>

std::forward_list::begin

      iterator begin() noexcept;
const_iterator begin() const noexcept;
Return iterator to beginning
Returns an iterator pointing to the first element in the forward_list container.

Notice that, unlike member forward_list::front, which returns a reference to the first element, this function returns a forward iterator pointing to it.

If the container is empty, the returned iterator value shall not be dereferenced.

Parameters

none

Return Value

An iterator to the beginning of the sequence container.

If the forward_list object is const-qualified, the function returns a const_iterator. Otherwise, it returns an iterator.

Member types iterator and const_iterator are forward iterator types (pointing to an element and to a const element, respectively).

Example

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// forward_list::begin example
#include <iostream>
#include <forward_list>

int main ()
{
  std::forward_list<int> mylist = { 34, 77, 16, 2 };

  std::cout << "mylist contains:";
  for ( auto it = mylist.begin(); it != mylist.end(); ++it )
    std::cout << ' ' << *it;

  std::cout << '\n';

  return 0;
}


Output:
mylist contains: 34 77 16 2

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed (neither the const nor the non-const versions modify the container).
No contained elements are accessed by the call, but the iterator returned can be used to access or modify elements. Concurrently accessing or modifying different elements is safe.

Exception safety

No-throw guarantee: this member function never throws exceptions.
The copy construction or assignment of the returned iterator is also guaranteed to never throw.

See also

  • 9316991614 2018-02-25
  • 191841613 2018-02-25
  • 16411612 2018-02-25
  • 6081981611 2018-02-25
  • 1784561610 2018-02-25
  • 4651609 2018-02-25
  • 9348111608 2018-02-25
  • 2513771607 2018-02-25
  • 6478461606 2018-02-24
  • 4985791605 2018-02-24
  • 5637141604 2018-02-24
  • 282181603 2018-02-24
  • 6217941602 2018-02-24
  • 5076141601 2018-02-24
  • 714281600 2018-02-24
  • 6607141599 2018-02-24
  • 949041598 2018-02-24
  • 6809961597 2018-02-24
  • 671871596 2018-02-24
  • 7107821595 2018-02-24