|Suppose foo.cpp contains just the one line:
|
|    int *x = false;

[ Is the above allowed? ]

I must admit I was surprised by this, but my reading of the
November 1997 Draft is that this is legal.  The value "false" is
a boolean literal, and bool is an integer type, so it qualifies
as an integral constant expression with value 0, and hence as a
null pointer constant.
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syd@quango.force9.co.uk wrote:
>
>
>
> Should VC5 have also displayed this error when the line said `false'?

I think it's technically legal, although I would have much
preferred to see a warning.

bool's are integral types.  false is therfore an integral
constant 0, and thus is a legal null pointer.
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Suppose foo.cpp contains just the one line:

    int *x = false;

then Microsoft VC5 SP3 displays no warnings or errors when compiling
using the command line:

    cl -W4 -c foo.cpp

However gcc 2.7 when compiling with:

    gcc -Wall -c foo.cpp

displays the error:

    foo.cpp:1: initialization to `int *' from `bool'

It looks like VC5 interprets the line as if it said:

    int *x = 0;

and then allows the cast to `int *'.  Note that changing the `false'
to `true' and then recompiling using VC5 displays the following error:

foo.cpp(1) : error C2440: 'initializing' : cannot convert from 'const bool'
             to 'int *'
             Conversion from integral type to pointer type requires
             reinterpret_cast, C-style cast or function-style cast

Should VC5 have also displayed this error when the line said `false'?

Geoff
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