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std::vector<T,Allocator>::append_range

From cppreference.com
< cpp‎ | container‎ | vector
 
 
 
 
template< container-compatible-range<T> R >
constexpr void append_range( R&& rg );
(since C++23)

Inserts copies of elements from the range rg before end(), in non-reversing order.

If after the operation the new size() is greater than old capacity() a reallocation takes place, in which case all iterators (including the end() iterator) and all references to the elements are invalidated. Otherwise only the end() iterator is invalidated.

Each iterator in rg is dereferenced exactly once.

Contents

[edit] Parameters

rg - a container compatible range, that is, an input_range whose elements are convertible to T
Type requirements
-
T must be EmplaceConstructible into vector from *ranges::begin(rg). Also, T must be MoveInsertable into vector. Otherwise, the behavior is undefined.

[edit] Return value

(none)

[edit] Complexity

If reallocation happens, linear in the number of elements of the resulting vector; otherwise, linear in the number of elements inserted plus the distance to the end().

[edit] Exceptions

If an exception is thrown other than by the copy constructor, move constructor, assignment operator, or move assignment operator of T or by any InputIterator operation there are no effects. If an exception is thrown while inserting a single element at the end and T is CopyInsertable or std::is_nothrow_move_constructible_v<T> is true, there are no effects. Otherwise, if an exception is thrown by the move constructor of a non-CopyInsertable T, the effects are unspecified.

Notes

Feature-test macro Value Std Feature
__cpp_lib_containers_ranges 202202L (C++23) Ranges-aware construction and insertion

[edit] Example

#include <cassert>
#include <vector>
#include <list>
 
int main()
{
    auto head = std::vector{1, 2, 3, 4};
    const auto tail = std::list{-5, -6, -7};
#ifdef __cpp_lib_containers_ranges
    head.append_range(tail);
#else
    head.insert(head.end(), tail.cbegin(), tail.cend());
#endif
    assert((head == std::vector{1, 2, 3, 4, -5, -6, -7}));
}

[edit] See also

inserts a range of elements
(public member function)
adds an element to the end
(public member function)
constructs an element in-place at the end
(public member function)