As many thanks As possible to who crates D and UFCS feature

[k-five via Digitalmars-d-learn]

I was waiting for a stable version of C++17 ( standard library ) 
to add some features of fileSystem in C++17 to my program that 
wants to iterate through all files in a directory recursively.

I was thinking how could I do for implementing that and add it to 
my program.

Now after starting to learn D ( nearby 2 weeks so far ). I can do 
it in 6 lines!

void main( string[] args ){
	
	string[] all_file_name =  dirEntries( ".", SpanMode.depth, false 
)
          .filter!( file => !file.name.matchFirst( regex( args[ 1 
] ) ).empty() )
          .filter!( file => ( args[ 2 ] == "-f" || args[ 2 ] == 
"-d"  ? ( args[ 2 ] == "-f" ? !file.isDir : !file.isFile ) : ( 
!file.isSymlink ) ) )
	 .map!( file => file.name )
	 .array;
	foreach( string item; all_file_name ) writeln( item );
	
}

./bin-file '[A-Z]$' -f   ---> print all files that are matched 
against [A-Z]$

./bin-file '[A-Z]$' -d   ---> print all directory that are 
matched against [A-Z]$

./bin-file '[A-Z]$' "anything-else"  ---> print both files and 
directory that are matched against [A-Z]$

I am so happy since after more than one year practicing in C++ 
and putting a collection more than 2000 examples of C++ on my 
github, I was not sure I could do it in 6 lines.

May it is a Spam but I think it is worth it.