From cppreference.com
iteratorerase(iteratorpos); (1)(until C++11)iteratorerase(const_iteratorpos);(since C++11)
(constexpr since C++20)iteratorerase(iteratorfirst,iteratorlast); (2)(until C++11)iteratorerase(const_iteratorfirst,const_iteratorlast);(since C++11)
(constexpr since C++20)Erases the specified elements from the container.
1) Removes the element at pos.
2) Removes the elements in the range [first, last).
Iterators (including the
iterator) and references to the elements at or after the point of the erase are invalidated.
The iterator pos must be valid and dereferenceable. Thus the
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 - the pair of iterators defining the
of elements to remove Type requirements -T must meet the requirements of
. Return value
Iterator following the last removed element.
1) If pos refers to the last element, then the
iterator is returned.
2) If last==end() prior to removal, then the updated
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.
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 minimize the number of moves of the remaining (non-removed) elements, — this is the erase-remove idiom.
replaces the erase-remove idiom.(since C++20)
Example
Run this code
#include<vector>#include<iostream>voidprint_container(conststd::vector<int>&c){for(inti:c)std::cout<<i<<' ';std::cout<<'\n';}intmain(){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 numbersfor(std::vector<int>::iteratorit=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 Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR Applied to Behavior as published Correct behavior
C++98 first was required to be dereferenceable, which
made the behavior of clearing an empty vector undefined not required if
first==last
C++98 iterators at the point of erase were not invalidated they are also invalidated See also