Re: Passing a String to a C/C++ Subprogram (Special Case)

["Randy Brukardt" <randy@rrsoftware.com>]

"Martin" <martin@thedowies.com> wrote in message 
news:50cd020a-480f-4569-990b-b2861f628bc1@googlegroups.com...
On Wednesday, October 16, 2013 6:42:29 PM UTC+1, Eryndlia Mavourneen wrote:
...
>> In the Ada95 LRM (I have to use Ada95.), in the introduction to Annex B 
>> (B 2/3) it states:  "Support for interfacing to any foreign language is 
>> optional."
>>
>That looks like Ada2012 RM rather than Ada95 (or Ada2005) 
>[http://www.ada-auth.org/standards/12rm/html/RM-B.html].
>
>But I do like the Ada2012 wording...it seems clearer - either the compiler 
>has to indicate the lack of support; or exception has to be raised. If 
>neither of those occur then your code should work as expected.

This is one of the things that falls under the so-called "Dewar rule": the 
Ada Standard never says nonsense (even when it literally does :-). No one 
ever thought that all programming languages have to be supported for 
interfacing, or that it is acceptable to accept the pragmas without actually 
implementing them. Unfortunately, the RM never actually said that. We 
figured it was better that it says so explicitly, thus we added some wording 
in Ada 2012. (My recollection is that we attempted to do so for Ada 2005, 
but put the wording in the wrong place so it didn't appear to apply where it 
should have.)

                            Randy.