< cpp‎ | container‎ | deque
template< container-compatible-range<T> R >
void prepend_range( R&& rg );
(since C++23)

Inserts, in non-reversing order, copies of elements in rg before begin(). Each iterator in the range rg is dereferenced exactly once.

All iterators (including the end() iterator) are invalidated. No references are invalidated.


[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 deque from *ranges::begin(rg). Also, T must be MoveInsertable into deque and T satisfies MoveConstructible, MoveAssignable, and Swappable. Otherwise, the behavior is undefined.

[edit] Return value


[edit] Complexity

Linear in size of rg.

[edit] Notes

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

[edit] Example

#include <algorithm>
#include <cassert>
#include <deque>
#include <vector>
int main()
    auto container = std::deque{0, 1, 2, 3};
    const auto rg = std::vector{-3, -2, -1};
#if __cpp_lib_containers_ranges
    container.insert(container.begin(), rg.cbegin(), rg.cend());
    assert(std::ranges::equal(container, std::deque{-3, -2, -1, 0, 1, 2, 3}));

[edit] See also

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