Inconsistent <iomanip> behavior

I have the following code

cout << setfill('0') << setw(4) << hex << 100 << 100 << std::endl;

      

        
        
        
      

    

Output:

006464

      

        
        
        
      

    

If I want every number with a width of 4 I have to use

out << setfill('0') << setw(4) << hex << 100 << sew(4) << 100 << std::endl;

      

        
        
        
      

    

But if I want to print every number with hex and setfill ('0'), I only need to set setfill ('0') and std :: hex once.

Will C ++ design this on purpose? what is his intention?