std::end, std::cend

Defined in header `<iterator>`
	(1)
template< class C > auto end( C& c ) -> decltype(c.end());		(since C++11) (until C++17)
template< class C > constexpr auto end( C& c ) -> decltype(c.end());		(since C++17)
	(1)
template< class C > auto end( const C& c ) -> decltype(c.end());		(since C++11) (until C++17)
template< class C > constexpr auto end( const C& c ) -> decltype(c.end());		(since C++17)
	(2)
template< class T, std::size_t N > T* end( T (&array)[N] );		(since C++11) (until C++14)
template< class T, std::size_t N > constexpr T* end( T (&array)[N] ) noexcept;		(since C++14)
template< class C > constexpr auto cend( const C& c ) noexcept(/* see below */) -> decltype(std::end(c));	(3)	(since C++14)

Returns an iterator to the end (i.e. the element after the last element) of the given container c or array array. These templates rely on C::end() having a reasonable implementation.

1) Returns exactly c.end(), which is typically an iterator one past the end of the sequence represented by c. If C is a standard Container, this returns a C::iterator when c is not const-qualified, and a C::const_iterator otherwise.

2) Returns a pointer to the end of the array array.

3) Returns exactly std::end(c), with c always treated as const-qualified. If C is a standard Container, this always returns a C::const_iterator.

Parameters

c	-	a container with an `end` method
array	-	an array of arbitrary type

Return value

An iterator to the end of c or array. Note that the end of a container or array is defined as the element following the last valid element.

Exceptions

noexcept specification:

noexcept(noexcept(std::end(c)))

Notes

In addition to being included in <iterator>, std::end and std::cend are guaranteed to become available if any of the following headers are included: <array>, <deque>, <forward_list>, <list>, <map>, <regex>, <set>, <span> (since C++20), <string>, <string_view> (since C++17), <unordered_map>, <unordered_set>, and <vector>.

User-defined overloads

Custom overloads of end may be provided for classes that do not expose a suitable end() member function, yet can be iterated. The following overloads are already provided by the standard library:

std::end(std::initializer_list) (C++11)	specializes `std::end` (function template)
std::end(std::valarray) (C++11)	specializes `std::end` (function template)
begin(std::filesystem::directory_iterator)end(std::filesystem::directory_iterator)	range-based for loop support (function)
begin(std::filesystem::recursive_directory_iterator)end(std::filesystem::recursive_directory_iterator)	range-based for loop support (function)

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);
    while (it != end_it) {
        f(*it);
        ++it;
    }
}

Example

#include <iostream>
#include <vector>
#include <iterator>
#include <algorithm>
 
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 a[] = { 5, 10, 15 };
    if (std::find(std::begin(a), std::end(a), 5) != std::end(a)) {
        std::cout << "found a 5 in array a!\n";
    }
}

Output:

found a 5 in array a!