std::ranges::view_interface<D>::operator[]

template<ranges::random_access_range R = D>
constexpr decltype(auto) operator[]( ranges::range_difference_t<R> n );

template<ranges::random_access_range R = const D>
constexpr decltype(auto) operator[]( ranges::range_difference_t<R> n ) const;

The default implementation of operator[] member function obtains the element at the specified offset relative to the beginning iterator, reusing the operator[] of the iterator type.

Parameters

Return value

The element at offset n relative to the beginning iterator.

Notes

In C++20, no type derived from std::ranges::view_interface in the standard library provides their own operator[] member function.

However, following derived types cannot use the default implementations, as they never satisfy random_access_range:

• std::ranges::basic_istream_view
• std::ranges::filter_view
• std::ranges::join_view
• std::ranges::lazy_split_view
• std::ranges::split_view

The inherited operator[] member function is available for std::ranges::empty_view, but a call to it always results in undefined behavior.

Example