The published class grammar looks like:

ClassBodyDeclaration:
	Declaration
	Constructor
	Destructor
	StaticConstructor
	StaticDestructor
	Invariant
	UnitTest
	ClassAllocator
	ClassDeallocator

However, the Declaration grammar doesn't permit a construct such as

synchronized ~this () {}

  or

const {
  void fn1 () {}
  void fn2 () {}
}

The rest of the docs clearly expect this kind of construction to be allowed.  I believe the fix is to modify the class body grammar to:

ClassBodyDeclaration:
   	DeclDef               <-- this is the change
	Constructor
	Destructor
	StaticConstructor
	StaticDestructor
	Invariant
	UnitTest
	ClassAllocator
	ClassDeallocator