Re: Using Ada.Containers.Vector and Limited Private types

[Gene <gene.ressler@gmail.com>]

On Jul 11, 6:06 pm, "Jeffrey R. Carter"
<spam.jrcarter....@spam.acm.org> wrote:
> Gene wrote:
>
> > But as Dmitry pointed out, what I wrote has some portability risk.  To
> > avoid this, just copy the bits you need into your own (non-limited)
> > data structure.
>
> > with Ada.Text_IO;            use Ada.Text_IO;
> > with Ada.Integer_Text_IO;    use Ada.Integer_Text_IO;
> > with Ada.Containers.Vectors;
> > with Ada.Directories;        use Ada.Directories;
> > with Ada.Calendar;           use Ada.Calendar; -- for comparing  date/
> > times
>
> > procedure List_By_Date is
>
> >    type String_Ptr_Type is access String;
> >    type File_Info_Type is
> >       record
> >          Modification_Time : Time;
> >          Simple_Name : String_Ptr_Type; -- Freed with storage pool!
>
> I would recommend using Ada.Strings.Unbounded.Unbounded_String with its
> automatic and tested memory management over implementing new and untested memory
> allocation and management yourself.
>
> --
> Jeff Carter
> "Well, a gala day is enough for me. I don't think
> I can handle any more."
> Duck Soup
> 93- Hide quoted text -
>
> - Show quoted text -

Right.  I initially did it with UBS and changed it. Unbounded_String,
at least in the GNAT implementation, is a super heavyweight.  In this
case, you call Simple_Name to get a string and then convert it to an
unbounded string.  In Ada 95 you'd have to convert back to a simple
String for printing; fortunately that's fixed in 2005.  Nonetheless
the syntax and the compiled code are both unsatisfying.  Barnes seems
to agree:

... conversion between bounded and unbounded strings and the raw type
String is required rather a lot and is both ugly and inefficient.

I do not find that relying on a simple new' and storage pool for
release to be a very intimidating form of memory management.