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In article <1deqlgINNmc0@darkstar.UCSC.EDU>, daniel@cse.ucsc.edu (Daniel R. Edelson) writes:> 
> 	new const int;
> 
> This allocates an uninitialized const object. 
> Seems like this should be explicitly prohibited (assuming
> there's no constructor, of course.) Is it?
> ...
> None of the compilers I tested detected this error.

Borland 3.1 does detect it. In fact I don't think it is necessary for a
compiler to spot such a mistake as the action of `new const int' is perfectly
well defined even if utterly useless!

BTW Borland rejects    `new const A' (an implicit call to A::A()) but not
`new const A()' (an explicit call to A::A())

Does anyone know if this is the _standard_ behaviour?

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In article <1deqlgINNmc0@darkstar.UCSC.EDU> daniel@cse.ucsc.edu (Daniel R. Edelson) writes:
>
>Section 7.1.6 contains the following statement:
>
>	``Unless explicitly declared extern, a const
>	object does not have external linkage and
>	must be initialized.''
>
>Does that prohibit the following code?
>
>	new const int;
>
>This allocates an uninitialized const object. 

	IMHO there is no such thing as a const *object*. 'const' controls
the access to an object, const T and T are the same type (this not
how the ARM is written though).

	However,

	const int *p=new int;

makes p a pointer with const access to an undefined int. This is just like

	int x; // no init
	const int *p=&x;

>Seems like this should be explicitly prohibited (assuming
>there's no constructor, of course.) Is it?
>
>Incidently, section 5.3.3 says:
>
>	``If [a new-initializer is] not [present], the object
>	will start out with an unspecified value.''
>
>Thus, an unitialized const dynamic object has and keeps
>forever an unspecified value. This should be prohibited.

	Not necessarily. With p as above 

	*(int*)p=5; // p now points to 5, we can cast away const :-(

	And of course 

	x=5;

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