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From: Daryle Walker (darylew_at_[hidden])
Date: 2008-07-18 06:48:03

On Jul 18, 2008, at 5:07 AM, Daryle Walker wrote:

> On Jul 17, 2008, at 10:32 PM, David Abrahams wrote:
>> Then, if I understand you correctly, none of the built-in types are
>> Assignable.
>> char* p; // p is unintialized
>> char* q = p; // invalid
>> Yes, uninitialized is one of the valid states for a builtin type,
>> i.e. part of the type's invariants.
> Really, I was wondering about that (corner) case, especially since
> it can't be replicated (i.e. it's undefined to use such a state as
> a source). I'm thinking more about non-POD class types, which must
> have an initial state with the internal primitive objects initialized.

Well, I looked into it further. In C++ 2003, section 4.1 "Lvalue-to-
rvalue conversion" [conv.lval], paragraph 1, an uninitialized object
can only be used as an lvalue, converting it to a rvalue is undefined
behavior. This means that your program is illegitimate and we can't
count it as a counter-example.

Daryle Walker
Mac, Internet, and Video Game Junkie
darylew AT hotmail DOT com

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