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std::filesy...try::assign(3)   C++ Standard Libary  std::filesy...try::assign(3)

NAME
     std::filesystem::directory_entry::assign  -  std::filesystem::directory_en-
     try::assign

Synopsis
	void assign( const std::filesystem::path& p  ); 		     (1)
     (since C++17)
	void  assign(  const std::filesystem::path& p, std::error_code& ec   (2)
     (since C++17)
	);

	Assigns new content to the directory entry object. Sets the  path  to  p
     and calls
	refresh  to update the cached attributes. If an error occurs, the values
     of the
	cached attributes are unspecified.

	This function does not commit any changes to the filesystem.

Parameters
	p  - path to the filesystem object to which the directory entry will re-
     fer
	ec - out-parameter for error reporting in the non-throwing overload

Return value
	(none)

Exceptions
	Any overload not marked noexcept may throw std::bad_alloc if memory  al-
     location
	fails.

	1) Throws std::filesystem::filesystem_error on underlying OS API errors,
     constructed
	with  p  as  the  first path argument and the OS error code as the error
     code argument.
	2) Sets a std::error_code& parameter to the OS API error code if  an  OS
     API call
	fails, and executes ec.clear() if no errors occur.

Example
     // Run this code

      #include <filesystem>
      #include <fstream>
      #include <iostream>

      void print_entry_info(const std::filesystem::directory_entry& entry)
      {
	  if (std::cout << "The entry " << entry; not entry.exists())
	  {
	      std::cout << " does not exists on the file system\n";
	      return;
	  }
	  std::cout << " is ";
	  if (entry.is_directory())
	      std::cout << "a directory\n";
	  if (entry.is_regular_file())
	      std::cout << "a regular file\n";
	  /*...*/
      }

      int main()
      {
	  std::filesystem::current_path(std::filesystem::temp_directory_path());

	  std::filesystem::directory_entry	     entry{std::filesystem::cur-
     rent_path()};
	  print_entry_info(entry);

	  std::filesystem::path name{"cppreference.html"};
	  std::ofstream{name} << "C++";

	  std::cout << "entry.assign();\n";
	  entry.assign(entry/name);
	  print_entry_info(entry);

	  std::cout << "remove(entry);\n";
	  std::filesystem::remove(entry);
	  print_entry_info(entry); // the entry still contains old "state"

	  std::cout << "entry.assign();\n";
	  entry.assign(entry); // or just call entry.refresh()
	  print_entry_info(entry);
      }

Possible output:
      The entry "/tmp" is a directory
      entry.assign();
      The entry "/tmp/cppreference.html" is a regular file
      remove(entry);
      The entry "/tmp/cppreference.html" is a regular file
      entry.assign();
      The entry "/tmp/cppreference.html" does not exists on the file system

See also
	operator= assigns contents
		  (public member function)

http://cppreference.com 	   2024.06.10	    std::filesy...try::assign(3)
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