Re: 'Size hack for enumerated types

[AdaMagica <christ-usch.grein@t-online.de>]

On Monday, July 7, 2014 10:23:06 PM UTC+2, Victor Porton wrote:
> Simon Wright wrote:
> > Victor Porton <porton@narod.ru> writes:
> >> Where in the Reference Manual it is said that Ada enumeration types
> >> are "equivalent" to C int (=enum) type?
> > Annex B.1 (http://www.ada-auth.org/standards/12rm/html/RM-B-1.html),
> > 2  The Convention aspect is used to indicate that an Ada entity should
> >    use the conventions of another language.
> > 21 If the Convention aspect is specified for a type, then the type shall
> >    either be compatible with or eligible for the specified convention.
> No reason to assume either of:
> 1. Ada enumeration is compatible with C int/enum.
> 2. Ada enumeration is eligible for the specified convention (the convention 
> C).
> This is a work for a future standard.
> It seems that the current one does not assert neither 1 neither 2. :-(

B.1(21/3) says "shall", so RM 1.1.5(3) applies. The compiler must reject the code if the enumeration is not compatible with C.

B.1(2/3) only says "should". So what does this mean? I gather together with (21), we're safe to assume it works.