NAME¶

std::forward_list::insert_after - std::forward_list::insert_after

Synopsis¶

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

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 <string>
#include <iostream>
#include <vector>

template<typename T>
std::ostream& operator<<(std::ostream& s, const std::forward_list<T>& v) {
s.put('[');
char comma[3] = {'\0', ' ', '\0'};
for (const auto& e : v) {
s << comma << e;
comma[0] = ',';
}
return s << ']';
}

int main()
{
std::forward_list<std::string> words {"the", "frogurt", "is", "also", "cursed"};
std::cout << "words: " << words << '\n';

// insert_after (2)
auto beginIt = words.begin();
words.insert_after(beginIt, "strawberry");
std::cout << "words: " << words << '\n';

// insert_after (3)
auto anotherIt = beginIt;
++anotherIt;
anotherIt = words.insert_after(anotherIt, 2, "strawberry");
std::cout << "words: " << words << '\n';

// insert_after (4)
std::vector<std::string> V = { "apple", "banana", "cherry"};
anotherIt = words.insert_after(anotherIt, V.begin(), V.end());
std::cout << "words: " << words << '\n';

// insert_after (5)
words.insert_after(anotherIt, {"jackfruit", "kiwifruit", "lime", "mango"});
std::cout << "words: " << words << '\n';
}

Output:¶

words: [the, frogurt, is, also, cursed]
words: [the, strawberry, frogurt, is, also, cursed]
words: [the, strawberry, strawberry, strawberry, frogurt, is, also, cursed]
words: [the, strawberry, strawberry, strawberry, apple, banana, cherry, frogurt, is, also, cursed]
words: [the, strawberry, strawberry, strawberry, apple, banana, cherry, jackfruit, kiwifruit, lime, mango, frogurt, is, also, cursed]

See also¶

emplace_after constructs elements in-place after an element
(C++11) (public member function)
push_front inserts an element to the beginning
(C++11) (public member function)