deduction guides for std::ranges::subrange
From cppreference.com
| Defined in header <ranges>
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| template< std::input_or_output_iterator I, std::sentinel_for<I> S > subrange(I, S) -> subrange<I, S>; |
(1) | (since C++20) |
| template< std::input_or_output_iterator I, std::sentinel_for<I> S > subrange(I, S, /*make-unsigned-like-t*/<std::iter_difference_t<I>>) -> |
(2) | (since C++20) |
| template< ranges::borrowed_range<R> > subrange(R&&) -> |
(3) | (since C++20) |
| template< ranges::borrowed_range<R> > subrange(R&&, /*make-unsigned-like-t*/<ranges::range_difference_t<R>>) -> |
(4) | (since C++20) |
These deduction guides are provided for std::ranges::subrange.
1) Deduces the template arguments from the type of iterator and sentinel. The
subrange is sized if std::sized_sentinel_for<S, I> is satisfied, as determined by the default template argument.2) Deduces the template arguments from the type of iterator and sentinel, while the size of range is specified. The
subrange is always sized.3) Deduces the template arguments from the type of range. The
subrange is sized if the size can be obtained from the range or its iterator and sentinel.4) Deduces the template arguments from the type of range, while the size of range is specified. The
subrange is always sized.For the definition of /* make-unsigned-like-t */, see make-unsigned-like-t .
Notes
While constructing the subrange object,
- for (1,2), the behavior is undefined if the iterator-sentinel pair does not denote a valid range,
- for (2,4), the behavior is undefined if the given size is not equal to the size of the range.
Example
| This section is incomplete Reason: no example |
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3404 | C++20 | meaningless deduction guides from pair-like types were provided | removed |