From Jason Turner

[range.drop.overview]

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  #### Overview <a id="range.drop.overview">[[range.drop.overview]]</a>
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- `drop_view` produces a `view` excluding the first N elements from
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- another `view`, or an empty range if the adapted `view` contains fewer
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- than N elements.
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  The name `views::drop` denotes a range adaptor object
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  [[range.adaptor.object]]. Let `E` and `F` be expressions, let `T` be
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  `remove_cvref_t<decltype((E))>`, and let `D` be
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  `range_difference_t<decltype((E))>`. If `decltype((F))` does not model
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  `convertible_to<D>`, `views::drop(E, F)` is ill-formed. Otherwise, the
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  expression `views::drop(E, F)` is expression-equivalent to:
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- - If `T` is a specialization of `ranges::empty_view`
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- [[range.empty.view]], then `((void) F, decay-copy(E))`.
 
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  - Otherwise, if `T` models `random_access_range` and `sized_range` and
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  is
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- - a specialization of `span` [[views.span]] where
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- `T::extent == dynamic_extent`,
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  - a specialization of `basic_string_view` [[string.view]],
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- - a specialization of `ranges::iota_view` [[range.iota.view]], or
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- - a specialization of `ranges::subrange` [[range.subrange]],
 
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  then
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- `T{ranges::begin(E) + min<D>(ranges::size(E), F), ranges::end(E)}`,
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- except that `E` is evaluated only once.
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- - Otherwise, `ranges::drop_view{E, F}`.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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  [*Example 1*:
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  ``` cpp
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  auto ints = views::iota(0) | views::take(10);
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- auto latter_half = drop_view{ints, 5};
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- for (auto i : latter_half) {
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  cout << i << ' '; // prints 5 6 7 8 9
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  }
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  ```
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  — *end example*]
 
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  #### Overview <a id="range.drop.overview">[[range.drop.overview]]</a>
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+ `drop_view` produces a view excluding the first N elements from another
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+ view, or an empty range if the adapted view contains fewer than N
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+ elements.
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  The name `views::drop` denotes a range adaptor object
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  [[range.adaptor.object]]. Let `E` and `F` be expressions, let `T` be
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  `remove_cvref_t<decltype((E))>`, and let `D` be
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  `range_difference_t<decltype((E))>`. If `decltype((F))` does not model
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  `convertible_to<D>`, `views::drop(E, F)` is ill-formed. Otherwise, the
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  expression `views::drop(E, F)` is expression-equivalent to:
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+ - If `T` is a specialization of `empty_view` [[range.empty.view]], then
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+ `((void)F, decay-copy(E))`, except that the evaluations of `E` and `F`
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+ are indeterminately sequenced.
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  - Otherwise, if `T` models `random_access_range` and `sized_range` and
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  is
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+ - a specialization of `span` [[views.span]],
 
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  - a specialization of `basic_string_view` [[string.view]],
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+ - a specialization of `iota_view` [[range.iota.view]], or
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+ - a specialization of `subrange` [[range.subrange]] where
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+ `T::StoreSize` is `false`,
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  then
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+ `U(ranges::begin(E) + std::min<D>(ranges::distance(E), F), ranges::end(E))`,
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+ except that `E` is evaluated only once, where `U` is
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+ `span<typename T::element_type>` if `T` is a specialization of `span`
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+ and `T` otherwise.
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+ - Otherwise, if `T` is a specialization of `subrange` [[range.subrange]]
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+ that models `random_access_range` and `sized_range`, then
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+ `T(ranges::begin(E) + std::min<D>(ranges::distance(E), F), ranges::{}end(E),
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+ to-unsigned-like(ranges::distance(E) -
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+ std::min<D>(ranges::distance(E), F)))`, except that `E` and `F` are
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+ each evaluated only once.
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+ - Otherwise, if `T` is a specialization of `repeat_view`
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+ [[range.repeat.view]]:
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+ - if `T` models `sized_range`, then
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+ ``` cpp
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+ views::repeat(*E.value_, ranges::distance(E) - std::min<D>(ranges::distance(E), F))
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+ ```
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+
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+ except that `E` is evaluated only once;
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+ - otherwise, `((void)F, decay-copy(E))`, except that the evaluations
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+ of `E` and `F` are indeterminately sequenced.
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+ - Otherwise, `drop_view(E, F)`.
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  [*Example 1*:
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  ``` cpp
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  auto ints = views::iota(0) | views::take(10);
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+ for (auto i : ints | views::drop(5)) {
 
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  cout << i << ' '; // prints 5 6 7 8 9
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  }
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  ```
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  — *end example*]