Re: Ada.strings.bounded problems?

[sparre@meyer.fys.ku.dk (Jacob Sparre Andersen)]

Keith Thompson (kst@alsys.com) wrote:

[ Mats.Weber@matrix.ch and ncohen@watson.ibm.com wrote about problems with 
  implementing Bounded_String. ]

|^^^^^^^^^^
| In Ada 95, it's very easy to have a case like the above where the
| user-defined "=" operator for a subcomponent is bypassed.  Section II-6.3
| of the Rationale, which discusses overloading of "=" and "/=", doesn't
| mention this problem.  Quite possibly it was simply overlooked.
|
| It's obviously too late to fix this in the language by requiring
| predefined "=" to invoke user-defined "=" for subcomponents.
|
| I suggest that Ada 95 compilers should issue a warning for a type
| whose predefined "=" operator bypasses a user-defined "=" operator
| for a subcomponent.  Determining exactly when to issue such a warning
| may be difficult ("=" can be declared to return a type other than
| Standard.Boolean, the left and right operands can be different types,
| "=" and "/=" can be overloaded separately in some circumstances, the
| declaration for "=" needn't be in the same scope as the operand type(s),
| etc.), but catching the most common cases shouldn't be difficult.
|__________

I agree with KT's suggestion about compiler warnings.
Is it allready time to start writing down what to do with Ada0X? Is somebody 
making a (mental) note of this problem for the '0X team, and where should 
such comments be sent?

Regards,
                Jacob Sparre Andersen
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