std::vector<T,Allocator>::erase
Min standard notice:
Erases the specified elements from the container.
# Declarations
iterator erase( iterator pos );
(until C++11)
iterator erase( const_iterator pos );
(since C++11) (constexpr since C++20)
iterator erase( iterator first, iterator last );
(until C++11)
iterator erase( const_iterator first, const_iterator last );
(since C++11) (constexpr since C++20)
# Parameters
pos: iterator to the element to removefirst, last: range of elements to remove
# Return value
Iterator following the last removed element.
# 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 <vector>
#include <iostream>
void print_container(const std::vector<int>& c)
{
for (int i : c)
std::cout << i << ' ';
std::cout << '\n';
}
int main()
{
std::vector<int> c{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
print_container(c);
c.erase(c.begin());
print_container(c);
c.erase(c.begin() + 2, c.begin() + 5);
print_container(c);
// Erase all even numbers
for (std::vector<int>::iterator it = c.begin(); it != c.end();)
{
if (*it % 2 == 0)
it = c.erase(it);
else
++it;
}
print_container(c);
}
# Defect reports
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 151 | C++98 | first was required to be dereferenceable, whichmade the behavior of clearing an empty vector undefined | not required iffirst == last |
| LWG 414 | C++98 | iterators at the point of erase were not invalidated | they are also invalidated |