std::forward_list<T,Allocator>::prepend_range

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.

No iterators or 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 `forward_list` from `*ranges::begin(rg)`. 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

#include <algorithm>
#include <cassert>
#include <forward_list>
#include <vector>
 
int main()
{
    auto container = std::forward_list{0, 1, 2, 3};
    const auto rg = std::vector{-3, -2, -1};
 
#if __cpp_lib_containers_ranges
    container.prepend_range(rg);
#else
    container.insert_after(container.before_begin(), rg.cbegin(), rg.cend());
#endif
    assert(std::ranges::equal(container, std::forward_list{-3, -2, -1, 0, 1, 2, 3}));
}

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