Folder traversal code C ++ (Win32 platform)

Recently, I continued to learn C ++ and wrote code for Traversing folders. I hope you can advise me.

1. Void common: file: readfiles (const wstring & directory, const wstring & Extentions, void (* filemethod) (const wstring &))
2. {
3. Win32_find_data finddata;
4. Zeromemory (& finddata, sizeof (finddata); // initialize finddata
6. Wstring findfilename (directory );
7. Wstring fulldirectoryname (directory );
8. If (directory [directory. Length ()-1] = '//')
9. {
10. Findfilename + = Extentions;
11. Fulldirectoryname = directory;
12. }
13. Else
14. {
15. Findfilename + = l' // '+ Extentions;
16. Fulldirectoryname + = l '//';
17. }
19. Handle hfind = findfirstfile (findfilename. c_str (), & finddata );
21. 
    

If (hfind = invalid_handle_value)
Return;

Findnextfile (hfind, & finddata );

Vector <wstring> dirlist;
While (findnextfile (hfind, & finddata ))
{
If (finddata. dwfileattributes & file_attribute_directory) = file_attribute_directory)
{
Dirlist. push_back (fulldirectoryname + finddata. cfilename );
}
Else

{
Wstring fullfilename (fulldirectoryname + finddata. cfilename );
Filemethod (fullfilename); // What do you do to traverse a file?
}
}

3. For (vector <wstring >:: iterator iter = dirlist. Begin ();
4. ITER! = Dirlist. End (); ++ ITER)
5. {
6. Readfiles (* ITER, Extentions, filemethod );
7. }
8. }

In this Code, I used a function pointer to process what to do after traversing a file. The declaration method of C ++ function pointers is really great. If you can support writing to lambda expressions, it is perfect.