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std::basic_string_view::size,std::basic_string_view::length(3) C++ Standard Libary std::basic_string_view::size,std::basic_string_view::length(3)

NAME

std::basic_string_view::size,std::basic_string_view::length - std::basic_string_view::size,std::basic_string_view::length

Synopsis


constexpr size_type size() const noexcept; (since C++17)
constexpr size_type length() const noexcept; (since C++17)


Returns the number of CharT elements in the view, i.e. std::distance(begin(),
end()).

Parameters


(none)

Return value


The number of CharT elements in the view.

Complexity


Constant.

Example

// Run this code


#include <iostream>
#include <string_view>


// Print a string surrounded by single quotes, its
// length and whether it is considered empty.
void check_string(std::string_view ref)
{
std::cout << std::boolalpha
<< "'" << ref << "' has " << ref.size()
<< " character(s); emptiness: " << ref.empty() << '\n';
}


int main(int argc, char **argv)
{
// An empty string
check_string("");


// Almost always not empty: argv[0]
if (argc > 0)
check_string(argv[0]);
}

Possible output:


'' has 0 character(s); emptiness: true
'./a.out' has 7 character(s); emptiness: false

See also


empty checks whether the view is empty
(public member function)
max_size returns the maximum number of characters
(public member function)
size returns the number of characters
length (public member function of std::basic_string<CharT,Traits,Allocator>)

2024.06.10 http://cppreference.com