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

is defined as *add-const-if*`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::`

is an associated class of the arguments.*sentinel*<Const>

The `!=`

operator is synthesized from `operator==`

.

y | - | `std::counted_iterator` to compare |

x | - | sentinel to compare |

`y.count() == 0 || y.base() == x.end_`

, where

denotes the underlying sentinel.*end_*

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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