std::basic_string<CharT,Traits,Allocator>::at

`reference at( size_type pos );`		(C++20)
`constexpr reference at( size_type pos );`		(C++20)
`const_reference at( size_type pos ) const;`		(C++20)
`constexpr const_reference at( size_type pos ) const;`		(C++20)

pos std::out_of_range

pos

-

pos >= size() std::out_of_range

Run this code

#include <stdexcept>
#include <iostream>
#include <string>

int main()
{
    std::string s("message"); // for capacity

    s = "abc";
    s.at(2) = 'x'; // ok
    std::cout << s << '\n';

    std::cout << "string size = " << s.size() << '\n';
    std::cout << "string capacity = " << s.capacity() << '\n';

    try {
        // throw, even if capacity allowed to access element
        s.at(3) = 'x';
    }
    catch (std::out_of_range const& exc) {
        std::cout << exc.what() << '\n';
    }
}

:

abx
string size = 3
string capacity = 7
basic_string::at

operator[]

() [edit]






(C++20)





(C++20)




(C++17)
(C++11)
(C++11)
(C++11)

cppreference.com

std::basic_string<CharT,Traits,Allocator>::at