Non-Retaining Collections

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Overview

For collections that don't retain their objects.

Non-retaining collections have historically been used when we needed more than one delegate in an object. However, NSNotificationCenter is a much better solution for n > 1 delegates. Using a non-retaining collection is dangerous, so if you must use one, use it with extreme care. The danger primarily lies in the fact that by all appearances the collection should still operate like a regular collection, so this might lead to a lot of developer error if the developer assumes that the collection does, in fact, retain the object.

Functions
NSMutableArray *	NICreateNonRetainingMutableArray (void)
NSMutableDictionary *	NICreateNonRetainingMutableDictionary (void)
NSMutableSet *	NICreateNonRetainingMutableSet (void)

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Function Documentation

NICreateNonRetainingMutableArray

(

void

)

Creates a mutable array which does not retain references to the objects it contains.

Typically used with arrays of delegates.

• [test] Verify that the retain count of objects aren't modified when added to and removed from non-retaining arrays.

Definition at line 23 of file NINonRetainingCollections.m.

NICreateNonRetainingMutableDictionary

(

void

)

Creates a mutable dictionary which does not retain references to the values it contains.

Typically used with dictionaries of delegates.

• [test] Verify that the retain count of objects aren't modified when added to and removed from non-retaining dictionaries.

Definition at line 29 of file NINonRetainingCollections.m.

NICreateNonRetainingMutableSet

(

void

)

Creates a mutable set which does not retain references to the values it contains.

Typically used with sets of delegates.

• [test] Verify that the retain count of objects aren't modified when added to and removed from non-retaining sets.

Definition at line 35 of file NINonRetainingCollections.m.