hacks/const_ref

class ConstRef < Object

In C, there are two types of constant pointers:
1. A constant pointer, so the pointer cannot change
2. A pointer to a constant; the pointer can change, but the object cannot be changed through this pointer (even though the object itself may not be a constant).

Ruby's constants are like #1, above.

Ruby has frozen objects, but no built-in equivalent to #2. A Const_Ref is a reference to an object that freezes the object before calling methods on it, and unfreezes the object when the method returns (if the object was not already frozen before the method was called).

This is not quite the same as a pointer to a constant, but is similar. It differs in the following example:

1. A holds a Const_Ref to B
2. C holds a reference to B
3. B holds a reference to C
4. A calls a method on B, which calls a method on C, which modifies B.

This method call will fail in Ruby; it would have succeded in C.

Public Methods

initialize(obj)

method_missing(*message, &block)

Requires