std::ranges::dangling (3) - Linux Manuals

std::ranges::dangling: std::ranges::dangling

NAME

std::ranges::dangling - std::ranges::dangling

Synopsis

Defined in header <ranges>
struct dangling; (since C++20)

dangling is a placeholder type and an empty class type, used together with the template aliases ranges::safe_iterator_t and ranges::safe_subrange_t.
When some constrain_algorithms that usually return an iterator or a subrange of a Range take a particular rvalue Range argument that does not models exposition-only concept __ForwardingRange, dangling will be returned instead to avoid returning potentially dangling results.

Member functions

 std::ranges::dangling::dangling

constexpr dangling() noexcept = default; (1)
template<class... Args> (2)
constexpr dangling(Args&&...) noexcept { }

1) dangling is trivially default constructible.
2) dangling can be constructed from arguments of arbitrary number and arbitrary non-void type. The construction does not have any side-effect itself.
In other words, after replacing the type (e.g. an iterator type) in a well-formed non-aggregate initialization with dangling, the resulting initialization is also well-formed.

Example

 This section is incomplete
 Reason: no example