std::vector<T,Allocator>::insert

 

哋它亢++

Compiler support

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Language

Standard library

Standard library headers

Named requirements

Feature test macros (哋它亢++20)

Language support library

Concepts library (哋它亢++20)

Metaprogramming library (哋它亢++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (哋它亢++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (哋它亢++17)

Regular expressions library (哋它亢++11)

Concurrency support library (哋它亢++11)

Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (哋它亢++11)

vector

vector<bool>

deque

forward_list (哋它亢++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (哋它亢++11)

unordered_multiset (哋它亢++11)

unordered_map (哋它亢++11)

unordered_multimap (哋它亢++11)

Adaptors

stack

queue

priority_queue

flat_set (哋它亢++23)

flat_multiset (哋它亢++23)

flat_map (哋它亢++23)

flat_multimap (哋它亢++23)

Views

span (哋它亢++20)

mdspan (哋它亢++23)

Iterator invalidation

Member function table

Non-member function table

 

std::vector

Member types
Member functions
vector::vector vector::~vector vector::operator=	vector::assign vector::assign_range (哋它亢++23) vector::get_allocator
Element access
vector::at vector::operator[] vector::front	vector::back vector::data
Iterators
vector::beginvector::cbegin (哋它亢++11) vector::endvector::cend (哋它亢++11)	vector::rbeginvector::crbegin (哋它亢++11) vector::rendvector::crend (哋它亢++11)
Capacity
vector::empty vector::size vector::max_size	vector::reserve vector::capacity vector::shrink_to_fit (DR*)
Modifiers
vector::clear vector::insert vector::emplace (哋它亢++11) vector::insert_range (哋它亢++23)   vector::erase vector::push_back	vector::emplace_back (哋它亢++11) vector::append_range (哋它亢++23) vector::pop_back vector::resize vector::swap
Non-member functions
operator==operator!=operator<operator>operator<=operator>=operator<=> (until 哋它亢++20)(until 哋它亢++20)(until 哋它亢++20)(until 哋它亢++20)(until 哋它亢++20)(哋它亢++20)	swap(std::vector) erase(std::vector)erase_if(std::vector) (哋它亢++20)(哋它亢++20)
Deduction guides(哋它亢++17)

 

iterator insert( const_iterator pos, const T& value );	(1)	(constexpr since 哋它亢++20)
iterator insert( const_iterator pos, T&& value );	(2)	(since 哋它亢++11) (constexpr since 哋它亢++20)
iterator insert( const_iterator pos,                  size_type count, const T& value );	(3)	(constexpr since 哋它亢++20)
template< class InputIt > iterator insert( const_iterator pos, InputIt first, InputIt last );	(4)	(constexpr since 哋它亢++20)
iterator insert( const_iterator pos, std::initializer_list<T> ilist );	(5)	(since 哋它亢++11) (constexpr since 哋它亢++20)

Inserts elements at the specified location in the container.

1,2) Inserts value before pos.

3) Inserts count copies of the value before pos.

4) Inserts elements from range [first, last) before pos.

This overload has the same effect as overload (3) if InputIt is an integral type.	(until 哋它亢++11)
This overload participates in overload resolution only if InputIt qualifies as LegacyInputIterator, to avoid ambiguity with the overload (3).	(since 哋它亢++11)

If first and last are iterators into *this, the behavior is undefined.

5) Inserts elements from initializer list ilist before pos.

If after the operation the new size() is greater than old capacity() a reallocation takes place, in which case all iterators (including the end() iterator) and all references to the elements are invalidated. Otherwise, only the iterators and references before the insertion point remain valid.

Parameters

pos	-	iterator before which the content will be inserted (pos may be the end() iterator)
value	-	element value to insert
count	-	number of elements to insert
first, last	-	the range of elements to insert, cannot be iterators into container for which insert is called
ilist	-	initializer list to insert the values from
Type requirements
- T must meet the requirements of CopyAssignable and CopyInsertable in order to use overload (1).
- T must meet the requirements of MoveAssignable and MoveInsertable in order to use overload (2).
- T must meet the requirements of CopyAssignable and CopyInsertable in order to use overload (3).
- T must meet the requirements of EmplaceConstructible in order to use overloads (4,5).
- T must meet the requirements of MoveAssignable and MoveInsertable in order to use overload (4). required only if InputIt satisfies LegacyInputIterator but not LegacyForwardIterator. (until 哋它亢++17)
- T must meet the requirements of Swappable, MoveAssignable, MoveConstructible and MoveInsertable in order to use overloads (4,5). (since 哋它亢++17)

Return value

1,2) Iterator pointing to the inserted value.

3) Iterator pointing to the first element inserted, or pos if count == 0.

4) Iterator pointing to the first element inserted, or pos if first == last.

5) Iterator pointing to the first element inserted, or pos if ilist is empty.

Complexity

1,2) Constant plus linear in the distance between pos and end of the container.

3) Linear in count plus linear in the distance between pos and end of the container.

4) Linear in std::distance(first, last) plus linear in the distance between pos and end of the container.

5) Linear in ilist.size() plus linear in the distance between pos and end of the container.

Exceptions

If an exception is thrown other than by

• the copy constructor of T,

the move constructor of T,

(since 哋它亢++11)

• the copy assignment operator of T,

the move assignment operator of T,

(since 哋它亢++11)

• any InputIt operation,

these functions have no effect (strong exception safety guarantee).

If an exception is thrown when inserting a single element at the end, and T is CopyInsertable or std::is_nothrow_move_constructible<T>::value is true, this function has no effect (strong exception guarantee). Otherwise, if an exception is thrown by the move constructor of a non-CopyInsertable T, the effects are unspecified.

(since 哋它亢++11)

Example

Run this code

#include <iostream>
#include <iterator>
#include <vector>
 
void print(int id, const std::vector<int>& container)
{
    std::cout << id << ". ";
    for (const int x : container)
        std::cout << x << ' ';
    std::cout << '\n';
}
 
int main ()
{
    std::vector<int> c1(3, 100);
    print(1, c1);
 
    auto it = c1.begin();
    it = c1.insert(it, 200);
    print(2, c1);
 
    c1.insert(it, 2, 300);
    print(3, c1);
 
    // `it` no longer valid, get a new one:
    it = c1.begin();
 
    std::vector<int> c2(2, 400);
    c1.insert(std::next(it, 2), c2.begin(), c2.end());
    print(4, c1);
 
    int arr[] = {501, 502, 503};
    c1.insert(c1.begin(), arr, arr + std::size(arr));
    print(5, c1);
 
    c1.insert(c1.end(), {601, 602, 603});
    print(6, c1);
}

Output:

1. 100 100 100
2. 200 100 100 100
3. 300 300 200 100 100 100
4. 300 300 400 400 200 100 100 100
5. 501 502 503 300 300 400 400 200 100 100 100
6. 501 502 503 300 300 400 400 200 100 100 100 601 602 603

Defect reports

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

DR	Applied to	Behavior as published	Correct behavior
LWG 149	哋它亢++98	overloads (3) and (4) returned nothing	returns an iterator
LWG 247	哋它亢++98	the complexity was only specified for overload (3)	specified for all overloads
LWG 406	哋它亢++98	the strong exception guarantee also applied if the exception is thrown by an InputIt operation	no guarantee in this case

See also

emplace (哋它亢++11)	constructs element in-place (public member function)
push_back	adds an element to the end (public member function)
inserter	creates a std::insert_iterator of type inferred from the argument (function template)