Re: When to do a constraint check and not ??

["Peter Hend�n" <phenden@tdab.com>]

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"Per Sandberg" wrote:
> procedue bla is
> b : boolean; --< B may contain any bit pattern at this point.

> procedure test( p : in out boolean ) is
> begin
> b := false;
> end test;

> begin
> test(b); --<< Is the compiler allowed to insert a constraint check on b
> here ??
> end;

> Is the answer that it is up to the wendor.
> I did not get any clues from the LRM.

The main clues are in 3.3.1, 13.9.1 and H.1 of ARM. There are some
comments in the same sections of the AARM.

My interpretation: The compiler is allowed, but not required, to raise
Constraint_Error or Program_Error exactly at (before) the call to test
in your example.

I'd be happy to hear from anyone more knowledgable than me on this,
even if my Coding Rules would still be to require initialization of all
objects at the earliest possible place, ie. normally at declaration.

Regards,
Peter Hend�n

--
Peter Hend�n           http://www.algonet.se/~phenden
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