Re: Question about generics.

[Jean-Pierre Rosen <rosen@adalog.fr>]

Peter C. Chapin a �crit :
> "Jeffrey R. Carter" <spam.not.jrcarter@acm.not.spam.org> wrote in
> news:7Q2qg.812592$084.507058@attbi_s22: 
> 
>> Peter C. Chapin wrote:
>>> generic
>>>   Size : in Integer;
>>> package Xyzzy is
>>>   type Index is mod Size;
>>>   -- etc.
>>> end Xyzzy;
>> What does a Size of -7 mean?
> 
> Why not a compile time error when the instantiation is attempted?
> 
Because in Ada, legality is checked when the generic is compiled.
*If* the generic compiles, and *if* parameters in the instantiation 
match the formals, *then* the instantiation is guaranteed to be correct, 
without rechecking the expanded form.

This is a useful and important difference from C++ templates.
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            J-P. Rosen (rosen@adalog.fr)
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