std::ranges::subrange<I,S,K>::subrange

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< cpp‎ | ranges‎ | subrange
 
 
Ranges library
Range adaptors
 
 
subrange() requires std::default_initializable<I> = default;
(1) (since C++20)
constexpr subrange( /*convertible-to-non-slicing*/<I> auto i, S s )
    requires (!/*StoreSize*/);
(2) (since C++20)
constexpr subrange( /*convertible-to-non-slicing*/<I> auto i, S s,

                    /*make-unsigned-like-t*/<std::iter_difference_t<I>> n )

    requires (K == ranges::subrange_kind::sized);
(3) (since C++20)
template< /*different-from*/<subrange> R >

    requires ranges::borrowed_range<R> &&
             /*convertible-to-non-slicing*/<ranges::iterator_t<R>, I> &&
             std::convertible_to<ranges::sentinel_t<R>, S>
constexpr subrange( R&& r )

    requires (!/*StoreSize*/ || ranges::sized_range<R>);
(4) (since C++20)
template< ranges::borrowed_range R>

    requires /*convertible-to-non-slicing*/<ranges::iterator_t<R>, I> &&
           std::convertible_to<ranges::sentinel_t<R>, S>
constexpr subrange( R&& r,
                    /*make-unsigned-like-t*/<std::iter_difference_t<I>> n )
    requires (K == ranges::subrange_kind::sized)

    : subrange{ranges::begin(r), ranges::end(r), n} {}
(5) (since C++20)

Constructs a subrange.

For the definitions of /*make-unsigned-like-t*/ and /*different-from*/, see make-unsigned-like-t and different-from respectively.

 Overload  Data members
begin_ end_ size_
(only if StoreSize is true)
(1) value-initialized value-initialized initialized with 0
(2) initialized with std::move(i) initialized with s N/A
(3) initialized with n
(4) initialized with std::move(ranges::begin(r)) initialized with ranges::end(r) initialized with static_cast<decltype(size_ )>
    (ranges::size(r))
(5) initialized with n
2) If [is) is not a valid range, the behavior is undefined.
3) If any of the following conditions is satisfied, the behavior is undefined:

Parameters

i - iterator that denotes the beginning of the range
s - sentinel that denotes the end of the range
r - range
n - size hint, must be equal to the size of the range

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
P2393R1 C++20 for overload (4), size_ might be initialized with ranges::size(r), but it is
not always implicitly convertible to the corresponding unsigned-integer-like type
made the
conversion explicit