__unaligned

When a pointer is declared as __unaligned, the compiler assumes that the type or data pointed to is not aligned. __unaligned is only valid in compilers for x64 and the Itanium Processor Family (IPF).

Remarks

When declaring a pointer to a structure that may not have aligned data, you can use the __unaligned keyword to tell the compiler that the type must be read one byte at a time.

By default, pointers are aligned.

For more information about alignment, see,

• align (C++)

• __alignof Operator

• pack

• /Zp (Struct Member Alignment)

• Examples of Structure Alignment (x64 specific)

Example

// unaligned_keyword.cpp
// compile with: /c
// processor: x64 IPF
#include <stdio.h>
int main() {
   char buf[100];

   int __unaligned *p1 = (int*)(&buf[37]);
   int *p2 = (int *)p1;

   *p1 = 0;   // ok

   __try {
      *p2 = 0;  // throws an exception
   }
   __except(1) {
      puts("exception");
   }
}

See Also

Concepts

C++ Keywords