NAME

std::basic_string_view::at - std::basic_string_view::at

Synopsis

constexpr const_reference at( size_type pos ) const; (since C++17)

Returns a const reference to the character at specified location pos. Bounds
checking is performed, exception of type std::out_of_range will be thrown on invalid
access.

Parameters

pos - position of the character to return

Return value

Const reference to the requested character.

Exceptions

Throws std::out_of_range if pos >= size().

Complexity

Constant.

Example

// Run this code

#include <iostream>
#include <stdexcept>
#include <string_view>

int main()
{
std::string_view str_view("abcdef");

try {
for (std::size_t i = 0; true; ++i)
std::cout << i << ": " << str_view.at(i) << '\n';
}
catch (const std::out_of_range& e) {
std::cout << "Whooops. Index is out of range.\n";
std::cout << e.what() << '\n';
}
}

Possible output:

0: a
1: b
2: c
3: d
4: e
5: f
6: Whooops. Index is out of range.
basic_string_view::at: __pos (which is 6) >= this->size() (which is 6)

See also

operator[] accesses the specified character
(C++17) (public member function)
at accesses the specified character with bounds checking
(public member function of std::basic_string<CharT,Traits,Allocator>)