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NNTP-Posting-Date: Sat, 26 Jul 2014 14:06:33 -0500
Date: Sat, 26 Jul 2014 15:06:32 -0400
From: Peter Chapin <PChapin@vtc.vsc.edu>
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Subject: Re: Troubles with C strings
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Xref: news.eternal-september.org comp.lang.ada:21260
Date: 2014-07-26T15:06:32-04:00
List-Id: <comp.lang.ada>

On 2014-07-26 11:15, Shark8 wrote:

> On 26-Jul-14 08:13, Victor Porton wrote:
>> Also: It seems that in Interfaces.C.Strings there is no function which
>> creates an Ada string of specified length from a chars_ptr (without
>> checking for NUL).
> 
> Such a function cannot exist: to determine the length of a C-style
> string you *must* scan through it for the terminating NULL. What you
> describe would be a "substring" method that can read beyond the
> string-bounds without raising an error... and I see no way that would
> end well.

Well the function could exist; it would just require an additional
parameter to specify how much should be copied. While such an approach
might be contrary to the sensibilities of Ada programmers, I don't think
C programmers would find it shocking.

Of course we are talking about an Ada interface here so adding a
function that by its nature could easily lead to undefined behave...
er... erroneous execution probably wouldn't be great.