std::ranges::concat_view<Views...>::begin
From cppreference.com
constexpr /*iterator*/<false> begin()
requires (!(/*simple-view*/<Views> && ...));
|
(1) | (since C++26) |
constexpr /*iterator*/<true> begin() const
requires (ranges::range<const Views> && ...) &&
/*concatable*/<const Views...>;
|
(2) | (since C++26) |
Returns an iterator to the beginning of the concat_view.
1) Equivalent to
iterator <false> it(this, std::in_place_index<0>,
ranges::begin(std::get<0>(views_ )));
it.template satisfy <0>();
return it;
2) Equivalent to
iterator <true> it(this, std::in_place_index<0>,
ranges::begin(std::get<0>(views_ )));
it.template satisfy <0>();
return it;
Return value
As specified above.
Example
The preliminary version can be checked out on Compiler Explorer.
Run this code
#include <ranges>
#include <string_view>
using namespace std::literals;
int main()
{
static constexpr auto c = {"🐱", "🐶"};
static constexpr auto a = {"🤡"sv};
static constexpr auto t = {"💚"sv};
static constexpr auto cat{std::views::concat(c, a, t)};
static_assert(*cat.begin() == "\U0001F431" and
cat.begin()[1] == "🐶" and
*(cat.begin() + 2) == "\N{CLOWN FACE}");
}
See also
| returns an iterator or a sentinel to the end (public member function) | |
(C++20) |
returns an iterator to the beginning of a range (customization point object) |