std::forward_list<T,Allocator>::insert_after

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Containers library

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Tables

Iterator invalidation

Member function table

Non-member function table

 

std::forward_list

Member functions
forward_list::forward_list forward_list::~forward_list forward_list::operator= forward_list::assign forward_list::assign_range (C++23)   forward_list::get_allocator Element access forward_list::front Iterators forward_list::before_beginforward_list::cbefore_begin forward_list::beginforward_list::cbegin forward_list::endforward_list::cend Capacity forward_list::empty forward_list::max_size	Modifiers forward_list::clear forward_list::emplace_front forward_list::push_front forward_list::insert_after forward_list::emplace_after forward_list::erase_after forward_list::insert_range_after (C++23) forward_list::prepend_range (C++23) forward_list::pop_front forward_list::resize forward_list::swap Operations forward_list::merge forward_list::splice_after forward_list::removeforward_list::remove_if forward_list::reverse forward_list::unique forward_list::sort
Non-member functions
operator==operator<=> (C++20) swap(std::forward_list) erase(std::forward_list)erase_if(std::forward_list) (C++20)(C++20)	operator!=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Deduction guides (C++17)

 

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

Inserts elements after the specified position in the container.

1,2) Inserts value after the element pointed to by pos.

3) Inserts count copies of the value after the element pointed to by pos.

4) Inserts elements from range [first, last) after the element pointed to by pos. The behavior is undefined if first and last are iterators into *this.

5) Inserts elements from initializer list ilist.

No iterators or references are invalidated.

Parameters

pos	-	iterator after which the content will be inserted
value	-	element value to insert
count	-	number of copies to insert
first, last	-	the range of elements to insert
ilist	-	initializer list to insert the values from
Type requirements
- InputIt must meet the requirements of LegacyInputIterator.

Return value

1,2) Iterator to the inserted element.

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

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

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

Exceptions

If an exception is thrown for any reason, these functions have no effect (strong exception safety guarantee).

Complexity

1,2) Constant.

3) Linear in count.

4) Linear in std::distance(first, last).

5) Linear in ilist.size().

Example

Run this code

#include <forward_list>
#include <iostream>
#include <string>
#include <vector>
 
void print(const std::forward_list<int>& list)
{
    std::cout << "list: {";
    for (char comma[3] = {'\0', ' ', '\0'}; int i : list)
    {
        std::cout << comma << i;
        comma[0] = ',';
    }
    std::cout << "}\n";
}
 
int main()
{
    std::forward_list<int> ints{1, 2, 3, 4, 5};
    print(ints);
 
    // insert_after (2)
    auto beginIt = ints.begin();
    ints.insert_after(beginIt, -6);
    print(ints);
 
    // insert_after (3)
    auto anotherIt = beginIt;
    ++anotherIt;
    anotherIt = ints.insert_after(anotherIt, 2, -7);
    print(ints);
 
    // insert_after (4)
    const std::vector<int> v = {-8, -9, -10};
    anotherIt = ints.insert_after(anotherIt, v.cbegin(), v.cend());
    print(ints);
 
    // insert_after (5)
    ints.insert_after(anotherIt, {-11, -12, -13, -14});
    print(ints);
}

Output:

list: {1, 2, 3, 4, 5}
list: {1, -6, 2, 3, 4, 5}
list: {1, -6, -7, -7, 2, 3, 4, 5}
list: {1, -6, -7, -7, -8, -9, -10, 2, 3, 4, 5}
list: {1, -6, -7, -7, -8, -9, -10, -11, -12, -13, -14, 2, 3, 4, 5}

See also

emplace_after	constructs elements in-place after an element (public member function)
push_front	inserts an element to the beginning (public member function)