std::ranges::view_interface<D>::operator[]
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< cpp | ranges | view interface
template<ranges::random_access_range R = D> constexpr decltype(auto) operator[]( ranges::range_difference_t<R> n ); |
(1) | (since C++20) |
template<ranges::random_access_range R = const D> constexpr decltype(auto) operator[]( ranges::range_difference_t<R> n ) const; |
(2) | (since C++20) |
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.
2) Same as (1), except that
derived
is static_cast<const D&>(*this).Parameters
n | - | position of the element to return |
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
This section is incomplete Reason: no example |