Re: for S'Image use Func??

[Gautier write-only <gautier_niouzes@hotmail.com>]

On May 11, 12:39 am, Yannick Duchêne (Hibou57)
<yannick_duch...@yahoo.fr> wrote:

[...]
> Well, to be honest, this is not exactly the same as with C, as  
> Ada.Streams.Stream_Element is implementation defined (which is good,  
> because this is indeed platform dependent), so you will need an Assert  
> pragma somewhere is your application, which ensures  
> Ada.Streams.Stream_Element is 8 bits or at least 8 bits (this is, in most  
> of case), and then convert from Ada.Streams.Stream_Element to your  
> Byte_Type or anything your application defined as such.

As Dmitry already wrote, you usually don't need to bother about it:
just use the stream attributes: Byte'Read/'Write(stream, b) and don't
worry at all about Stream_Element being 8 bits or not...
There are two exceptions I know:
- the Read in Ada.Streams gives the number of bytes actually read when
a stream reach its end
- in some implementations, Byte_array'Read/'Write are utterly slow
compared to the procedures in Ada.Streams.
Anyway, you don't need to bet or assume that
Ada.Streams.Stream_Element is 8 bits.
You can make a size check (even a compile-time one!). Here, for
arrays:
  subtype Size_test_a is Byte_Array(1..19);
  subtype Size_test_b is Ada.Streams.Stream_Element_Array(1..19);
  --
  is_mapping_possible: constant Boolean:=
    Size_test_a'Size = Size_test_b'Size and then
    Size_test_a'Alignment = Size_test_b'Alignment;
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