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

 

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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 during insert_after there are no effects (strong exception 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)