NAME

std::vector::erase - std::vector::erase

Synopsis

iterator erase( iterator pos ); (until C++11)
iterator erase( const_iterator pos ); (since C++11)
(until C++20)
constexpr iterator erase( const_iterator pos ); (since C++20)
iterator erase( iterator first, iterator last ); (1) (until C++11)
iterator erase( const_iterator first, (since C++11)
const_iterator last ); (2) (until C++20)
constexpr iterator erase( const_iterator first, (since C++20)
const_iterator last );

Erases the specified elements from the container.

1) Removes the element at pos.
2) Removes the elements in the range [first, last).

Invalidates iterators and references at or after the point of the erase, including
the end() iterator.

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

pos - iterator to the element to remove
first, last - range of elements to remove

Type requirements

-
T must meet the requirements of MoveAssignable.

Return value

Iterator following the last removed element.

If pos refers to the last element, then the end() iterator is returned.

If last==end() prior to removal, then the updated end() iterator is returned.

If [first, last) is an empty range, then last is returned.

Exceptions

Does not throw unless an exception is thrown by the assignment operator of T.

Complexity

Linear: the number of calls to the destructor of T is the same as the number of
elements erased, the assignment operator of T is called the number of times equal to
the number of elements in the vector after the erased elements

Example

// Run this code

#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 (C++11 and later)
for (std::vector<int>::iterator it = c.begin(); it != c.end(); ) {
if (*it % 2 == 0) {
it = c.erase(it);
} else {
++it;
}
}
print_container(c);
}

Output:

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