public member function
<forward_list>

std::forward_list::clear

void clear() noexcept;
Clear content
Removes all elements from the forward_list container (which are destroyed), and leaving the container with a size of 0.

Parameters

none

Return value

none

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
// clearing forward_list
#include <iostream>
#include <forward_list>

int main ()
{
  std::forward_list<int> mylist = { 10, 20, 30 };

  std::cout << "mylist contains:";
  for (int& x: mylist) std::cout << ' ' << x;
  std::cout << '\n';

  mylist.clear();
  mylist.insert_after( mylist.before_begin(), {100, 200} );

  std::cout << "mylist contains:";
  for (int& x: mylist) std::cout << ' ' << x;
  std::cout << '\n';

  return 0;
}

Output:
mylist contains: 10 20 30
mylist contains: 100 200


Complexity

Linear in size (destructions).

Iterator validity

All iterators, references and pointers related to this container are invalidated, except the end iterators.

Data races

The container is modified.
All contained elements are modified.

Exception safety

No-throw guarantee: this member function never throws exceptions.

See also