NAME¶

std::list::splice - std::list::splice

Synopsis¶

void splice( const_iterator pos, list& other ); (1)
void splice( const_iterator pos, list&& other ); (2) (since C++11)
void splice( const_iterator pos, list& other, const_iterator it ); (3)
void splice( const_iterator pos, list&& other, const_iterator it (4) (since C++11)
);
void splice( const_iterator pos, list& other, (5)
const_iterator first, const_iterator last);
void splice( const_iterator pos, list&& other, (6) (since C++11)
const_iterator first, const_iterator last );

Transfers elements from one list to another.

No elements are copied or moved, only the internal pointers of the list nodes are
re-pointed. No iterators or references become invalidated, the iterators to moved
elements remain valid, but now refer into *this, not into other.

1,2) Transfers all elements from other into *this. The elements are inserted before
the element pointed to by pos. The container other becomes empty after the
operation.
3,4) Transfers the element pointed to by it from other into *this. The element is
inserted before the element pointed to by pos.
5,6) Transfers the elements in the range [first, last) from other into *this. The
elements are inserted before the element pointed to by pos.

The behavior is undefined if

* get_allocator() != other.get_allocator(),
* for overloads (1,2), *this and other refer to the same object,
* for overloads (3,4), it is not a dereferenceable iterator into other, or
* for overloads (5,6),

* [first, last) is not a valid range in other, or
* pos is in [first, last).

Parameters¶

pos - element before which the content will be inserted
other - another container to transfer the content from
it - the element to transfer from other to *this
first, last - the range of elements to transfer from other to *this

Return value¶

(none)

Exceptions¶

Throws nothing.

Complexity¶

1-4) Constant.
5,6) Constant if other refers to the same object as *this, otherwise linear in
std::distance(first, last).

Example¶

// Run this code

#include <iostream>
#include <list>

std::ostream& operator<<(std::ostream& ostr, const std::list<int>& list)
{
for (auto& i : list)
ostr << ' ' << i;

return ostr;
}

int main ()
{
std::list<int> list1{1, 2, 3, 4, 5};
std::list<int> list2{10, 20, 30, 40, 50};

auto it = list1.begin();
std::advance(it, 2);

list1.splice(it, list2);

std::cout << "list1:" << list1 << '\n';
std::cout << "list2:" << list2 << '\n';

list2.splice(list2.begin(), list1, it, list1.end());

std::cout << "list1:" << list1 << '\n';
std::cout << "list2:" << list2 << '\n';
}

Output:¶

list1: 1 2 10 20 30 40 50 3 4 5
list2:
list1: 1 2 10 20 30 40 50
list2: 3 4 5

Defect reports

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

DR Applied to Behavior as published Correct behavior
references and iterators to the moved they refer or point to
LWG 250 C++98 element(s) were all invalidated the
same element(s) in *this
N2525 C++98 O(1) splicing could not be guaranteed if the behavior is
get_allocator() != other.get_allocator() undefined in this case

See also¶

merge merges two sorted lists
(public member function)
remove removes elements satisfying specific criteria
remove_if (public member function)