The package Ada.Strings.Unbounded.Text_IO
in library files a-suteio.ads/adb contains some GNAT-specific
subprograms useful for Text_IO operations on unbounded strings:
Put (To_String (U)) except that an extra copy is avoided.
New_Line.
Similar to the effect of Put_Line (To_String (U)) except
that an extra copy is avoided.
In the above procedures, File is of type Ada.Text_IO.File_Type
and is optional. If the parameter is omitted, then the standard input or
output file is referenced as appropriate.
The package Ada.Strings.Wide_Unbounded.Wide_Text_IO in library
files a-swuwti.ads/adb provides similar extended Wide_Text_IO
functionality for unbounded wide strings.