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An Associative Sequence allows efficient retrieval of elements based on keys. Like associative sequences in MPL, and unlike associative containers in STL, Fusion associative sequences have no implied ordering relation. Instead, type identity is used to impose an equivalence relation on keys. Keys are not checked for uniqueness.
Notation
sAn Associative Sequence
SAn Associative Sequence type
KAn arbitrary key type
oAn arbitrary object
eA Sequence element
For any Associative Sequence the following expressions must be valid:
| Expression | Return type | Type Requirements | Runtime Complexity | 
|---|---|---|---|
| 
                     | MPL Boolean Constant. Convertible to bool. | Constant | |
| 
                     | Any type | Constant | |
| 
                     | Any type | 
                     | Constant | 
| Expression | Compile Time Complexity | 
|---|---|
| 
                     | Amortized constant time | 
| 
                     | Amortized constant time | 
| 
                     | Amortized constant time | 
| ![[Note]](../../../../../../../doc/src/images/note.png) | Note | 
|---|---|
| 
             | 
| Expression | Semantics | 
|---|---|
| 
                     | 
                    A boolean Integral Constant  | 
| 
                     | 
                    The element associated with the key  | 
set
            map
            filter_view
              (where adapted sequence is an Associative
              Sequence and a Forward
              Sequence)
            iterator_range
              (where adapted iterators are Associative
              Iterators)
            joint_view
              (where adapted sequences are Associative
              Sequences and Forward
              Sequences)
            reverse_view
              (where adapted sequence is an Associative
              Sequence and a Bidirectional
              Sequence)