Re: Constraint checking of actuals passed to Attributes

[Keith Thompson <kst@cts.com>]

Matt Brennan <zschub@hotmail.com> writes:
> Is an implementation required to generate code to check that an actual
> parameter passed to an attribute (for example, 'Image of a scalar type)
> is subtype conformant with the formal parameter? 

Yes, but the formal parameter may not be what you expect it to be.

In the specific case of 'Image, 3.5(35..36) says:

    S'Image denotes a function with the following specification: 

           function S'Image(Arg : S'Base)
             return String

So, for example, Natural'Image(-1) is the same as Integer'Image(-1),
and will not raise Constraint_Error.

-- 
Keith Thompson (The_Other_Keith) kst@cts.com  <http://www.ghoti.net/~kst>
San Diego Supercomputer Center           <*>  <http://www.sdsc.edu/~kst>
Welcome to the last year of the 20th century.