Re: Ada self-referential operators

[kst@thomsoft.com (Keith Thompson)]

In <3hg6gj$mkt@miranda.gmrc.gecm.com> bill@valiant (R.A.L Williams) writes:
[...]
> Obviously, any compiler which tried to optimise a basic block containing
> that would be in for a nasty surprise! So, OK, we disable statement level
> optimisation where overloaded assignment is used. Caveat emptor (I don't
> know the latin for programmer) -- if you use this construct, don't expect
> optimisation.

Optimization isn't really an issue.  Optimizers typically operate on
some intermediate form (or sometimes on machine code).  A call to a
user-defined operator (assignment or otherwise) would appear to the
optimizer as an ordinary subprogram call, which it could optimize or
not just as if it were written explicitly using call notation.  If the
optimizer has access to the body of the subprogram (e.g., if it's declared
inline), it may be able to do something with it.

As for user-defined assignment, (as in

    procedure ":="(Target: in out Some_Type; Source: in Some_Other_Type);

) I'd love to see it in the language myself, but defining it really is
more complicated than it looks.  I don't claim to understand all the
issues, so I'll leave it to others to address them.

-- 
Keith Thompson (The_Other_Keith)  kst@thomsoft.com (kst@alsys.com still works)
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