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std::basic_string_view::at(3) C++ Standard Libarystd::basic_string_view::at(3)

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::ba-
       sic_string<CharT,Traits,Allocator>)

http://cppreference.com		  2022.07.31	 std::basic_string_view::at(3)

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