Will an implicit variable in a using clause be garbage collected?

Question

In the following code, does the underlying code contain a hard reference to the unnamed variable instance of type Foo, or is the item vulnerable to garbage collection?

using(new Foo())
{
    // Something done here.
}

The collected item is just a semaphore type object that performs some reference counting on resources so it isn't being referenced in the code block.

Answer 1

The using clause creates a hidden locally-scoped variable holding the object (this variable is used by the generated finally clause).

This variable prevents the object from being GC'd.

You can see this variable in the spec.