will the pointer survive?

[Allen]

Hi all,

Will my pointer survive this conversion?

MyType_tag MyType;
MyType_tag* pMyPntr = &MyType;
int iUglyTempStorage = (int)pMyPntr;
MyType_tag* pMyOtherPntr = (MyType_tag*)iUglyTempStorage;

 

[Ivan Vecerina]

Will my pointer survive this conversion?

MyType_tag MyType;
MyType_tag* pMyPntr = &MyType;
int iUglyTempStorage = (int)pMyPntr;
MyType_tag* pMyOtherPntr = (MyType_tag*)iUglyTempStorage;

No. (except on some platforms)


hth,
Ivan

 

[Chris Theis]

Hi all,

Will my pointer survive this conversion?

MyType_tag MyType;
MyType_tag* pMyPntr = &MyType;
int iUglyTempStorage = (int)pMyPntr;
MyType_tag* pMyOtherPntr = (MyType_tag*)iUglyTempStorage;

Not necessarily, though your conversion will (more or less) succeed as
you're forcing the compiler to obey your wish. Generally you might get away
with this on some platforms but it's not guaranteed to work and it's
certainly not portable.

Chris

 

[Unforgiven]

Hi all,

Will my pointer survive this conversion?

MyType_tag MyType;
MyType_tag* pMyPntr = &MyType;
int iUglyTempStorage = (int)pMyPntr;
MyType_tag* pMyOtherPntr = (MyType_tag*)iUglyTempStorage;

Only if you're using a platform where an int is the same size as a pointer.

 

[EventHelix.com]

int iUglyTempStorage = (int)pMyPntr;

The above line is the source of trouble. Here it assumes that the
pointer and the integer are of the same size. This may not be
true on several platforms.

Sandeep

 

[Nils Petter Vaskinn]

Will my pointer survive this conversion?

MyType_tag MyType;
MyType_tag* pMyPntr = &MyType;
int iUglyTempStorage = (int)pMyPntr;
MyType_tag* pMyOtherPntr = (MyType_tag*)iUglyTempStorage;

Will this work?


MyType_tag MyType;
MyType_tag* pMyPntr = &MyType;
char *ugly[sizof(MyType_tag*)];
memcpy(ugly,&pMyPtr,sizeof(MyType_tag*));
MyType_tag* pMyOtherPntr;
memcpy(&pMyOtherPntr,ugly,sizeof(MyType_tag*));


That made me feel really bad I think I have to go take a shower and
wash my mouth out with soap

 

[Allen]

The above line is the source of trouble. Here it assumes that the
pointer and the integer are of the same size. This may not be
true on several platforms.

But this should only be a compile-time issue, right? Once it's
compiled, the binary image should no longer be dependant on the sizes of
types on various platforms should it?

 

[Jack Klein]

But this should only be a compile-time issue, right? Once it's
compiled, the binary image should no longer be dependant on the sizes of
types on various platforms should it?

Once it's compiled, the binary image will not be compatible with
various platforms that have different sizes for types.

--
Jack Klein
Home: http://JK-Technology.Com
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[Rolf Magnus]

But this should only be a compile-time issue, right? Once it's
compiled, the binary image should no longer be dependant on the sizes
of types on various platforms should it?

Well, I don't know what you mean, but if you compile it for a platform
on which a pointer is bigger than an int (like e.g. virtually all 64bit
platforms), it will never work, even if there are other platforms on
which int and pointers are the same size.