std::end, std::cend
<array>
<deque>
<flat_map>
<flat_set>
<forward_list>
<inplace_vector>
<iterator>
<list>
<map>
<regex>
<set>
<span>
<string>
<string_view>
<unordered_map>
<unordered_set>
<vector>
auto end( C& c ) -> decltype(c.end());
(constexpr since C++17)
auto end( const C& c ) -> decltype(c.end());
(constexpr since C++17)
T* end( T (&array)[N] );
(noexcept since C++14)
(constexpr since C++14)
constexpr auto cend( const C& c ) noexcept(/* see below */)
Returns an iterator to the end (i.e. the element after the last element) of the given range.
[edit] Parameters
end
member function
[edit] Return value
[edit] Exceptions
[edit] Overloads
Custom overloads of end
may be provided for classes and enumerations that do not expose a suitable end()
member function, yet can be iterated. The following overloads are already provided by the standard library:
Similar to the use of swap
(described in Swappable), typical use of the end
function in generic context is an equivalent of using std::end; end(arg);, which lets both the ADL-selected overloads for user-defined types and the standard library function templates to appear in the same overload set.
template<typename Container, typename Function> void for_each(Container&& cont, Function f) { using std::begin ; auto it = begin(cont); using std::end; auto end_it = end(cont); for (; it != end_it; ++it) f(*it); }
Overloads of end
found by argument-dependent lookup can be used to customize the behavior of std::ranges::end , std::ranges::cend , and other customization pointer objects depending on std::ranges::end .
[edit] Notes
The non-array overloads exactly reflect the behavior of C::end(). Their effects may be surprising if the member function does not have a reasonable implementation.
std::cend
is introduced for unification of member and non-member range accesses. See also LWG issue 2128.
If C
is a shallow-const view, std::cend
may return a mutable iterator. Such behavior is unexpected for some users. See also P2276 and P2278.
[edit] Example
#include <algorithm> #include <iostream> #include <vector> int main() { std::vector <int> v = {3, 1, 4}; if (std::find (std::begin (v), std::end(v), 5) != std::end(v)) std::cout << "Found a 5 in vector v!\n"; int w[] = {5, 10, 15}; if (std::find (std::begin (w), std::end(w), 5) != std::end(w)) std::cout << "Found a 5 in array w!\n"; }
Output:
Found a 5 in array w!
[edit] See also
(function template) [edit]
(customization point object)[edit]