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std::basic_string_view::operator[](3) C++ Standard Libary std::basic_string_view::operator[](3)

NAME

std::basic_string_view::operator[] - std::basic_string_view::operator[]

Synopsis


constexpr const_reference operator[]( size_type pos ) const; (since C++17)


Returns a const reference to the character at specified location pos.


No bounds checking is performed: the behavior is undefined if pos >= size().

Parameters


pos - position of the character to return

Return value


Const reference to the requested character.

Exceptions


Does not throw.

Complexity


Constant.

Notes


Unlike std::basic_string::operator[], std::basic_string_view::operator[](size()) has
undefined behavior instead of returning CharT().

Example

// Run this code


#include <iostream>
#include <string_view>


int main()
{
std::string str = "Exemplar";
std::string_view v = str;
std::cout << v[2] << '\n';
// v[2] = 'y'; // Error: cannot modify through a string view
str[2] = 'y';
std::cout << v[2] << '\n';
}

Output:


e
y

See also


at accesses the specified character with bounds checking
(public member function)
accesses the specified character
operator[] (public member function of std::basic_string<CharT,Traits,Allocator>)

2024.06.10 http://cppreference.com