Enum std.bitmanip.member taggedClassRef

A tagged class reference uses the bits known to be zero in a normal class reference to store extra information. For example, a pointer to an integer must be 4-byte aligned, so there are 2 bits that are always known to be zero. One can store a 2-bit integer there.

The example above creates a tagged reference to an Object in the struct A. This expects the same parameters as taggedPointer, except the first argument which must be a class type instead of a pointer type.

Warning: Don't use taggedClassRef with references to garbage collected objects, as it will result in undefined behaviour. See http://dlang.org/garbage.html for details.

Declaration

enum taggedClassRef(T, string name, Ts...) = createTaggedReference!(createStoreName!(T, name, 0, Ts), T, 8, name, Ts).result;

Example

struct A
{
    int a;
    mixin(taggedClassRef!(
        Object, "o",
        uint, "i", 2));
}
A obj;
obj.o = new Object();
obj.i = 3;