How to redefine a struct initially in the shared header file from my own source .cpp/.h ?

Question

I've an shared header file, foo.h, with the following

typedef struct tagINFO {
    PINFO    info;
    FLAGS       flags;
    MASK        mask;
} INFO;

How can I redefine this typedef within my own .cpp or .h file?

I can't modify that foo.h, as this is shared. The modification is just for my own experiment so it's not appropriate to alter the shared foo.h.

Thanks.

Answer 1

I propose you add it to another namespace, eg test, in one of your headers:

namespace test
{
    typedef struct tagINFO {
        PINFO    info;
        FLAGS       flags;
        MASK        mask;
    } INFO;
}

Answer 2

How can I make your suggestion work for the following call?

BOOL GetInfo(
  _In_   UINT32 id,

  _Inout_  UINT32 *infoCount,

  _Out_  INFO *info
);

For example my new tagINFO is now like below,

namespace test
{
    typedef struct tagINFO {
        PINFO    info;
        FLAGS       flags;
        MASK        mask;
	UINT32    newField; 
    } INFO;
}

Thanks.

Answer 3

You can not 'redefine' a typedef. Perhaps if you describe what you are trying to accomplish, people may suggest something.

---

Yan

Answer 4

Try this:

typedef struct tagINFO2
{
    . . . .
} INFO2;

#define INFO INFO2

Answer 5

Do not follow this advice unless you understand everything that is going to happen (and this is what you want to happen). If the GetInfo function is compiled to work with the arrays if INFO structures and you are going to call it with array of INFO2 structures through this preprocessor trick, you may find things go out of hand very quickly.

---

Yan

Answer 6

Hope I can explain it right. Basically, GetInfo function can return the following

    typedef struct tagINFO {
        PINFO    info;
        FLAGS       flags;
        MASK        mask;
	UINT32    newField;     } INFO;

However, my SDK header was old, and didn't match the new struct returned by GetInfo().

So I need to create my own version of INFO matches what GetInfo() returns so the values returned won't mismatch to my old struct of INFO.

In this case, would Viorel suggestion work?

Thanks.

Answer 7

Yes.

---

Yan

Answer 8

How can I make your suggestion work for the following call?

BOOL GetInfo(
  _In_   UINT32 id,

  _Inout_  UINT32 *infoCount,

  _Out_  INFO *info
);

For example my new tagINFO is now like below,

namespace test
{
    typedef struct tagINFO {
        PINFO    info;
        FLAGS       flags;
        MASK        mask;
	UINT32    newField; 
    } INFO;
}

Thanks.

Use "test::INFO" instead of "INFO".

Or, add "using namespace test" to your code, following the include files. In this way, every "INFO" in the source file will be set to the redefined one.

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Damon Zheng [MSFT]
MSDN Community Support | Feedback to us

Answer 9

If it’s only for your experiment, go ahead and alter foo.h on your hard drive.  Make sure you rebuild all the modules that depend on it.

 

-- David

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