std::experimental::ranges::dangling, std::experimental::ranges::safe_iterator_t - cppreference.com (original) (raw)

| Defined in header <experimental/ranges/iterator> | | | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | ----------- | | template< CopyConstructible T > class dangling { public: dangling() requires DefaultConstructible<T>(); dangling(T t); T get_unsafe() const; }; | | (ranges TS) | | template< Range R > using safe_iterator_t = std::conditional_t<std::is_lvalue_reference<R>::value, ranges::iterator_t<R>, ranges::dangling<ranges::iterator_t<R>>; | | (ranges TS) |

The class template dangling is a simple wrapper around an object to indicate that the wrapped object may be dangling, that is, it refers to another object whose lifetime may have ended.

The alias template safe_iterator_t returns the iterator type of R, wrapped in dangling if the range was an rvalue range (as indicated by R not being an lvalue reference type).

They are used by range algorithms that accept rvalue ranges and return iterators into them.

[edit] Member functions

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

| dangling() requires DefaultConstructible<T>(); | (1) | | | ----------------------------------------------- | --- | | | dangling(T t); | (2) | |

1. Default constructor. Value-initializes the wrapped object.

2. Initializes the wrapped object with t. Note that this constructor defines an implicit conversion from T to dangling<T>.

std::experimental::ranges::dangling::get_unsafe

Returns a copy of the wrapped object.