Question

In C# you have nice alignment attributes such as this:

[StructLayout(LayoutKind.Explicit)]
public struct Message
{
    [FieldOffset(0)]
    public int a;
    [FieldOffset(4)]
    public short b;
    [FieldOffset(6)]
    public int c;
    [FieldOffset(22)] //Leave some empty space just for the heck of it.
    public DateTime dt;

}

Which gives you fine control on how you need your structure to be layed out in memory. Is there such a thing in standard C++?

Answer 1

Compilers typically support that via a #pragma but it’s not something that is included in the C++ standard and, thus, is not portable.

For an example with the Microsoft compiler, see: http://msdn.microsoft.com/en-us/library/2e70t5y1(VS.80).aspx