From cppreference.com
enumerate_view()requiresstd::default_initializable<V>=default; (1) (since C++23)constexprexplicitenumerate_view(Vbase); (2) (since C++23)Constructs a enumerate_view.
1) Default constructor.
the underlying view
. After construction,
returns a copy of V().
2) Initializes the underlying view
with std::move(base).
Parameters
base - the underlying view Example