NAME¶

std::deque::prepend_range - std::deque::prepend_range

Synopsis¶

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

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.

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.

Return value¶

(none)

Complexity¶

Linear in size of rg.

Notes¶

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

Example¶

// Run this code

#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.prepend_range(rg);
#else
container.insert(container.begin(), rg.cbegin(), rg.cend());
#endif
assert(std::ranges::equal(container, std::deque{-3, -2, -1, 0, 1, 2, 3}));
}

See also¶

append_range adds a range of elements to the end
(C++23) (public member function)
insert_range inserts a range of elements
(C++23) (public member function)
push_front inserts an element to the beginning
(public member function)
emplace_front constructs an element in-place at the beginning
(C++11) (public member function)