英語 での Reference count の使用例とその 日本語 への翻訳
{-}
- 
                        Colloquial
                    
- 
                        Ecclesiastic
                    
- 
                        Computer
                    
- 
                        Programming
                    
Automatic Reference Count(ARC).
Reference count with_narrow().
You need not increment its reference count.
An objects reference count generally starts at zero.
Reference count is incremented and var 1 also owns ownership.
When we call clone(), the Arc<T> needs to update the reference count.
An object whose reference count drops to zero is summarily deleted.
All Python objects(even Python integers) have a type and a reference count.
When the reference count becomes zero, the allocated memory is released automatically.
Another new macro, Py_CLEAR(obj), decreases the reference count of obj and sets obj to the null pointer.
When the reference count of an object hits 0(zero), the object deletes itself.
The ownership of object reference  of type_ptr moves to type var,so there is no increase or decrease of reference count.
For var 1, var 2, the reference count is decremented since it has passed the scope.
When the pointer no longers holds the address of that object,it has to decrease the reference count of that object by one.
If a call to Release() causes the reference count to hit zero, the object will generally free itself.
If the reference count reaches zero, the object's type's deallocation function(which must not be NULL) is invoked.
Holding relationships are used to model reference count based life-time management of the target Items.
If the reference count drops to zero and no other loaded libraries use symbols in it, then the dynamic library is unloaded.
For instance, instead of deleting an object whose reference count has been decremented to zero, the reaper performs no other action.
Because Perl uses reference counting,  as soon as we reach the end of the loop, the$io variable goes out of scope,so the reference count on the file object goes to zero, and it is immediately freed ie.
Structures are always deallocated when they reach 0 reference count and cannot be modified when they have -1 reference count.
This may cause the reference count for the object previously bound to the name to reach zero, causing the object to be deallocated and its destructor(if it has one) to be called.
It is a goodidea to use this macro whenever decrementing the reference count of an object that might be traversed during garbage collection.
Del__()- the former decrements the reference count  for x by one,and the latter is only called when x‘s reference count reaches zero.
Returns the currently owned reference  as release(decrement the reference count) and sets the reference  pointer to nil and returns it.
Del__()- the former decrements the reference count  for x by one,and the latter is only called when x‘s reference count reaches zero.
In the process of_narrow() processing, when the call to_narrow() succeeds,the reference count of the target object is incremented, but if it fails it is not incremented.
Del__()-- the former decrements the reference count  for by one,and the latter is only called when 's reference count reaches zero.
The overhead of individually deleting every object for which the reference count has been decremented to zero may be quite high, since every such deletion results in a transaction with the database.