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AfxIsValidAddress

Tests any memory address to ensure that it is contained entirely within the program's memory space.

BOOL AfxIsValidAddress(
   const void* lp,
   UINT nBytes,
   BOOL bReadWrite = TRUE 
); 

Parameters

lp
Points to the memory address to be tested.
nBytes
Contains the number of bytes of memory to be tested.
bReadWrite
Specifies whether the memory is both for reading and writing (TRUE) or just reading (FALSE).

Return Value

In debug builds, nonzero if the specified memory block is contained entirely within the program's memory space; otherwise 0.

In non-debug builds, nonzero if lp is not NULL; otherwise 0.

Remarks

The address is not restricted to blocks allocated by new.

Example

// Allocate a 5 character array, which should have a valid memory address.
char *array = new char[5];

// Create a null pointer, which should be an invalid memory address.
char *null = (char *)0x0;

ASSERT(AfxIsValidAddress(array, 5));
ASSERT(!AfxIsValidAddress(null, 5));

See Also

MFC Macros and Globals | AfxIsMemoryBlock | AfxIsValidString

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