Version 1.2 of acs/ac-00275.txt

!topic Predicate_Failure - expected type is String
!reference Ada 2012 RM3.2.4(14.3/4), (44/4); 11.3(2.1/4)
!from Christoph Grein 16-02-17
!discussion

With the introduction of the raise_expression, the expected type of
Predicate_Failure can no longer be pure String. The examples show this.
Should this be corrected?

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From: Randy Brukardt
Sent: Wednesday, February 17, 2016  2:27 PM

???
 
Raise expressions predated Predicate_Failure by more than a year. We had them
in mind from the beginning; the use of type String for Predicate_Failure was
invented after the fact (originally, Predicate_Failure could only take a raise
expression, but we had issues describing the expected type). So far as I'm
aware, there is no problem with writing:
 
    Predicate_Failure => (raise Constraint_Error with Even'Image &
                                                         " - value not even");
 
After all, a raise expression matches any type.
 
So what problem are you concerned about???

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