Structure Member

Use the alignment attribute to specify how to align a member in a structure.

For example, the following structure member definition aligns all definitions of struct S3 on an 8-byte boundary, where a is at offset 0 and b is at offset 8.

struct S3 { 
     char a; 
     int b __attribute__ ((aligned (8))); 
  }; 
  struct S3 s3;
  

The following struct member definition aligns all definitions of struct S4 on a 4-byte boundary, where a is at offset 0 and b is at offset 4.

struct S4 { 
     char a; 
     int b __attribute__ ((aligned (2))); 
  }; 
  struct S4 s4;