std::string_view end() method

od C++17

// Const version only
constexpr iterator end() const noexcept;

// Const version only
constexpr const_iterator cend() const noexcept;

Returns an iterator to the element past the end of the view.

If the array is empty, the returned iterator will be equal to begin().

Undefined Behavior

Attempting to dereference a past the end iterator is undefined behaviour.

Parameters

(none)

Return value

Iterator to the character following the last character.

Complexity

Constant - O(1).

Notes

For a container c, the expression *std::prev(c.end()) is equivalent to c.back().

Difference between end and cend

Unlike for other containers, like std::string or std::vector, end and cend both return the same iterator.

Non const container

end

#include <string_view>

int main()
{
    std::string_view str = "Hello";
    auto it = str.cend(); // Type: std::string_view::const_iterator
    *std::prev(it) = 'J'; // ❌ Error!
}

cend

#include <string_view>

int main()
{
    std::string_view str = "Hello";
    auto it = str.cend(); // Type: std::string_view::const_iterator
    *std::prev(it) = 'J'; // ❌ Error!
}

Const container

end

#include <string_view>

int main()
{
    const std::string_view str = "Hello";
    auto it = str.end(); // Type: std::string_view::const_iterator
    *std::prev(it) = 'J'; // ❌ Error! 
}

cend

#include <string_view>

int main()
{
    const std::string_view str = "Hello";
    auto it = str.cend(); // Type: std::string_view::const_iterator
    *std::prev(it) = 'J'; // ❌ Error! 
}

Example

Main.cpp

#include <iostream>
#include <iterator>
#include <string_view>
 
int main()
{
    std::string_view str_view("abcd");
 
    auto end = str_view.end();
    auto cend = str_view.cend();
 
    std::cout << *std::prev(end) << '\n';
    std::cout << *std::prev(cend) << '\n';
 
    std::cout << std::boolalpha << (end == cend) << '\n';
}

Output

d
d
true