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operator-(ranges::transform_view::sentinel)

friend constexpr ranges::range_difference_t<Base>
  operator-( const /*iterator*/<Const>& x, const /*sentinel*/& y )
    requires std::sized_sentinel_for<ranges::sentinel_t<Base>, ranges::iterator_t<Base>>;
(1) (since C++20)
friend constexpr ranges::range_difference_t<Base>
  operator-( const /*sentinel*/& y, const /*iterator*/<Const>& x )
    requires std::sized_sentinel_for<ranges::sentinel_t<Base>, ranges::iterator_t<Base>>;
(2) (since C++20)

Computes the distance between the underlying iterator of x and the underlying sentinel of y.

These functions are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when transform_view::sentinel<Const> is an associated class of the arguments.

Parameters

x - an iterator
y - a sentinel

Return value

Let current_ denote the underlying iterator, end_ denote the underlying sentinel.

1) x.current_ - y.end_
2) y.end_ - x.current_

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