std::list<T,Allocator>::erase

iterator erase( iterator pos );

iterator erase( const_iterator pos );

iterator erase( iterator first, iterator last );

iterator erase( const_iterator first, const_iterator last );

Erases the specified elements from the container.

References and iterators to the erased elements are invalidated. Other references and iterators are not affected.

The iterator pos must be valid and dereferenceable. Thus the end() iterator (which is valid, but is not dereferenceable) cannot be used as a value for pos.

The iterator first does not need to be dereferenceable if first == last: erasing an empty range is a no-op.

Parameters

Return value

Iterator following the last removed element.

Exceptions

(none).

Complexity

Notes

When container elements need to be erased based on a predicate, rather than iterating the container and calling unary erase, the iterator range overload is generally used with std::remove()/std::remove_if() to minimise the number of moves of the remaining (non-removed) elements, this is the erase-remove idiom. std::erase_if() replaces the erase-remove idiom. (since C++20).

Example

#include <list>
#include <iostream>
#include <iterator>
 
void print_container(const std::list<int>& c) 
{
    for (int i : c)
        std::cout << i << " ";
    std::cout << '\n';
}
 
int main( )
{
    std::list<int> c{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
    print_container(c);
 
    c.erase(c.begin());
    print_container(c);
 
    std::list<int>::iterator range_begin = c.begin();
    std::list<int>::iterator range_end = c.begin();
    std::advance(range_begin,2);
    std::advance(range_end,5);
 
    c.erase(range_begin, range_end);
    print_container(c);
 
    // Erase all even numbers
    for (std::list<int>::iterator it = c.begin(); it != c.end();)
    {
        if (*it % 2 == 0)
            it = c.erase(it);
        else
            ++it;
    }
    print_container(c);
}

0 1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9
1 2 6 7 8 9
1 7 9

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also