Memory leak when not assigning UnitOfWorkScope in using statement

[spongessuck]

When using IKernel.Get<T> in a using block, I was having issues with memory leaks as the objects created by IKernel.Get<T> were not being dereferenced and the GC never cleaned them up.

private IKernel kernel;
...
public T CreateInstance<T>()
{
    using(UnitOfWorkScope.Create())
        return this.kernel.Get<T>();
}

After refactoring like so, the problem went away:

public T CreateInstance<T>()
{
    T instance;
    using(var _ = UnitOfWorkScope.Create())
        instance = this.kernel.Get<T>();
    return instance;
}

The key was assigning the UnitOfWorkScope in the using statement. Even after moving the return outside of the using block, as soon as I removed the var _ = assignment the problem came back.

Not sure what to make of it.