Test for > 'last

[prichtmyer@yahoo.com (Peter Richtmyer)]

This may be trivial, but I have come across some code
in a (weapon control) system that does checks similar
to:

    ---------------------------------------
    if enum_input < enum_type'first or 
       enum_input > enum_type'last then 
       -- handle the input error
    ---------------------------------------

I have experimented, and found that this type of code
could do at least 3 different things, depending upon 
the compiler and error-checking options:

 - always say that "enum_input" is OK, regardless of its "validity"
 - always raise an exception when the data is invalid
 - work as intended

I think they were running the code with no exceptions
being raised.

I also think the code should be using the 'valid test instead.

But I am wondering whether people think the original code
is OK, sort of wrong, really grossly wrong, or what.

thanks,
Peter