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Showing content from https://cplusplus.github.io/LWG/issue4094 below:

Issue 4094: ranges::fold_meow is overconstrained

template<bidirectional_iterator I, sentinel_for<I> S, class T = iter_value_t<I>,
         indirectly-binary-right-foldable<T, I> F>
  constexpr auto ranges::fold_right(I first, S last, T init, F f);
template<bidirectional_range R, class T = range_value_t<R>,
         indirectly-binary-right-foldable<T, iterator_t<R>> F>
  constexpr auto ranges::fold_right(R&& r, T init, F f);

-3- Effects: Equivalent to:

using U = decay_t<invoke_result_t<F&, iter_reference_t<I>, T>>;
if (first == last)
  return U(std::move(init));
I tail = ranges::next(first, last);
U accum =(invoke(f, *--tail, std::move(init)));
while (first != tail)
  accum = invoke(f, *--tail, std::move(accum));
return accum;

[…]

template<input_iterator I, sentinel_for<I> S, class T = iter_value_t<I>,
         indirectly-binary-left-foldable<T, I> F>
  constexpr see below ranges::fold_left_with_iter(I first, S last, T init, F f);
template<input_range R, class T = range_value_t<R>,
         indirectly-binary-left-foldable<T, iterator_t<R>> F>
  constexpr see below ranges::fold_left_with_iter(R&& r, T init, F f);

-6- Let U be decay_t<invoke_result_t<F&, T, iter_reference_t<I>>>.

-7- Effects: Equivalent to:

if (first == last)
  return {std::move(first), U(std::move(init))};
U accum =(invoke(f, std::move(init), *first));
for (++first; first != last; ++first)
  accum = invoke(f, std::move(accum), *first);
return {std::move(first), std::move(accum)};

-8- Remarks: The return type is fold_left_with_iter_result<I, U> for the first overload and fold_left_with_iter_result<borrowed_iterator_t<R>, U> for the second overload.

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