std::filesystem::begin(directory_iterator),std::filesystem::end(directory_iterator)(3)

NAME
std::filesystem::begin(directory_iterator),std::filesystem::end(directory_iterator) - std::filesystem::begin(directory_iterator),std::filesystem::end(directory_iterator)

Synopsis
   Defined in header <filesystem>
   directory_iterator begin( directory_iterator iter ) noexcept; (1) (since C++17)
   directory_iterator end( directory_iterator ) noexcept; (2) (since C++17)
   1) Returns iter unchanged.
   2) Returns a default-constructed directory_iterator, which serves as the end
   iterator. The argument is ignored.
   These non-member functions enable the use of directory_iterators with range-based
   for loops
   and make directory_iterator a range type
   (since C++20).

Parameters
   iter - a directory_iterator

Return value
   1) iter unchanged.
   2) End iterator (default-constructed directory_iterator).

Example
// Run this code
 #include <filesystem>
 #include <fstream>
 #include <iostream>
 namespace fs = std::filesystem;
 int main()
 {
     fs::create_directories("sandbox/a/b");
     std::ofstream("sandbox/file1.txt");
     std::ofstream("sandbox/file2.txt");
     for (auto& p : fs::directory_iterator("sandbox"))
         std::cout << p << '\n';
     fs::remove_all("sandbox");
 }

Possible output:
 "sandbox/a"
 "sandbox/file1.txt"
 "sandbox/file2.txt"
   Defect reports
   The following behavior-changing defect reports were applied retroactively to
   previously published C++ standards.
      DR Applied to Behavior as published Correct behavior
   LWG 3480 C++17 end took the argument by reference takes the argument by value

See also
   begin(std::filesystem::recursive_directory_iterator) range-based for loop support
   end(std::filesystem::recursive_directory_iterator) (function)