std::basic_string_view<CharT,Traits>::size,std::basic_string_view<CharT,Traits>::length (3) - Linux Manuals

std::basic_string_view<CharT,Traits>::size,std::basic_string_view<CharT,Traits>::length: std::basic_string_view<CharT,Traits>::size,std::basic_string_view<CharT,Traits>::length

NAME

std::basic_string_view<CharT,Traits>::size,std::basic_string_view<CharT,Traits>::length - std::basic_string_view<CharT,Traits>::size,std::basic_string_view<CharT,Traits>::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 <string_view>
  #include <iostream>


  void check_string(std::string_view ref)
  {
          // Print a string surrounded by single quotes, its length
          // and whether it is considered empty.
          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


         checks whether the view is empty
empty (public member function)
         returns the maximum number of characters
max_size (public member function)

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