friend constexpr bool operator==( const std::counted_iterator<ranges::iterator_t<Base>>& y, const /*sentinel*/& x ); | (1) | (since C++20) |
template< bool OtherC = !Const > requires std::sentinel_for<ranges::sentinel_t<Base>, ranges::iterator_t</*add-const-if*/<OtherC, V>>> friend constexpr bool operator==( const std::counted_iterator<ranges::iterator_t< /*add-const-if*/<OtherC, V>>>& y, const /*sentinel*/& x ); | (2) | (since C++20) |
Compares a take_view::/*sentinel*/
with a std::counted_iterator
(typically obtained from a call to take_view::begin
).
Returns true
if y
points past the N-th element (where N is the number passed to the constructor of take_view
), or if end of underlying view is reached.
The exposition-only alias template add-const-if
is defined as template<bool C, class T> using /*add-const-if*/ = std::conditional_t<C, const T, T>;
.
These functions are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::ranges::take_view::sentinel<Const>
is an associated class of the arguments.
The !=
operator is synthesized from operator==
.
y | - | std::counted_iterator to compare |
x | - | sentinel to compare |
y.count() == 0 || y.base() == x.end_
, where end_
denotes the underlying sentinel.
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
---|---|---|---|
LWG 3449 | C++20 | comparison between the iterator and the sentinel of differently const-qualified take_view was unsupported | made supported when possible |
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