Controls how the members of a structure are packed into memory and specifies the same packing for all structures in a module.
/Zp[1|2|4|8|16]
Remarks
When you specify this option, each structure member after the first is stored on either the size of the member type or n-byte boundaries (where n is 1, 2, 4, 8, or 16), whichever is smaller.
The available values are described in the following table.
- 1 
 Packs structures on 1-byte boundaries. Same as /Zp.
- 2 
 Packs structures on 2-byte boundaries.
- 4 
 Packs structures on 4-byte boundaries.
- 8 
 Packs structures on 8-byte boundaries (default).
- 16 
 Packs structures on 16-byte boundaries.
You should not use this option unless you have specific alignment requirements.
You can also use pack to control structure packing. For more information about alignment, see:
- Examples of Structure Alignment (x64 specific) 
To set this compiler option in the Visual Studio development environment
- Open the project's Property Pages dialog box. For details, see How to: Open Project Property Pages. 
- Click the C/C++ folder. 
- Click the Code Generation property page. 
- Modify the Struct Member Alignment property.