26 Containers library [containers]

26.3 Sequence containers [sequences]

26.3.9 Class template forward_­list [forwardlist]

26.3.9.6 forward_­list operations [forwardlist.ops]

void splice_after(const_iterator position, forward_list& x); void splice_after(const_iterator position, forward_list&& x);

Requires: position is before_­begin() or is a dereferenceable iterator in the range [begin(), end()). get_­allocator() == x.get_­allocator(). &x != this.

Effects: Inserts the contents of x after position, and x becomes empty. Pointers and references to the moved elements of x now refer to those same elements but as members of *this. Iterators referring to the moved elements will continue to refer to their elements, but they now behave as iterators into *this, not into x.

Throws: Nothing.

Complexity: O(distance(x.begin(), x.end()))

void splice_after(const_iterator position, forward_list& x, const_iterator i); void splice_after(const_iterator position, forward_list&& x, const_iterator i);

Requires: position is before_­begin() or is a dereferenceable iterator in the range [begin(), end()). The iterator following i is a dereferenceable iterator in x. get_­allocator() == x.get_­allocator().

Effects: Inserts the element following i into *this, following position, and removes it from x. The result is unchanged if position == i or position == ++i. Pointers and references to *++i continue to refer to the same element but as a member of *this. Iterators to *++i continue to refer to the same element, but now behave as iterators into *this, not into x.

Throws: Nothing.

Complexity: O(1)

void splice_after(const_iterator position, forward_list& x, const_iterator first, const_iterator last); void splice_after(const_iterator position, forward_list&& x, const_iterator first, const_iterator last);

Requires: position is before_­begin() or is a dereferenceable iterator in the range [begin(), end()). (first, last) is a valid range in x, and all iterators in the range (first, last) are dereferenceable. position is not an iterator in the range (first, last). get_­allocator() == x.get_­allocator().

Effects: Inserts elements in the range (first, last) after position and removes the elements from x. Pointers and references to the moved elements of x now refer to those same elements but as members of *this. Iterators referring to the moved elements will continue to refer to their elements, but they now behave as iterators into *this, not into x.

Complexity: O(distance(first, last))

void remove(const T& value); template <class Predicate> void remove_if(Predicate pred);

Effects: Erases all the elements in the list referred by a list iterator i for which the following conditions hold: *i == value (for remove()), pred(*i) is true (for remove_­if()). Invalidates only the iterators and references to the erased elements.

Throws: Nothing unless an exception is thrown by the equality comparison or the predicate.

Remarks: Stable.

Complexity: Exactly distance(begin(), end()) applications of the corresponding predicate.

void unique(); template <class BinaryPredicate> void unique(BinaryPredicate pred);

Effects: Erases all but the first element from every consecutive group of equal elements referred to by the iterator i in the range [first + 1, last) for which *i == *(i-1) (for the version with no arguments) or pred(*i, *(i - 1)) (for the version with a predicate argument) holds. Invalidates only the iterators and references to the erased elements.

Throws: Nothing unless an exception is thrown by the equality comparison or the predicate.

Complexity: If the range [first, last) is not empty, exactly (last - first) - 1 applications of the corresponding predicate, otherwise no applications of the predicate.

void merge(forward_list& x); void merge(forward_list&& x); template <class Compare> void merge(forward_list& x, Compare comp); template <class Compare> void merge(forward_list&& x, Compare comp);

Requires: comp defines a strict weak ordering, and *this and x are both sorted according to this ordering. get_­allocator() == x.get_­allocator().

Effects: Merges the two sorted ranges [begin(), end()) and [x.begin(), x.end()). x is empty after the merge. If an exception is thrown other than by a comparison there are no effects. Pointers and references to the moved elements of x now refer to those same elements but as members of *this. Iterators referring to the moved elements will continue to refer to their elements, but they now behave as iterators into *this, not into x.

Remarks: Stable. The behavior is undefined if get_­allocator() != x.get_­allocator().

Complexity: At most distance(begin(), end()) + distance(x.begin(), x.end()) - 1 comparisons.

void sort(); template <class Compare> void sort(Compare comp);

Requires: operator< (for the version with no arguments) or comp (for the version with a comparison argument) defines a strict weak ordering.

Effects: Sorts the list according to the operator< or the comp function object. If an exception is thrown, the order of the elements in *this is unspecified. Does not affect the validity of iterators and references.

Remarks: Stable.

Complexity: Approximately NlogN comparisons, where N is distance(begin(), end()).

void reverse() noexcept;

Effects: Reverses the order of the elements in the list. Does not affect the validity of iterators and references.

Complexity: Linear time.