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A.18.13 The Generic Package Containers.Indefinite_Hashed_Maps

{AI95-00302-03} The language-defined generic package Containers.Indefinite_Hashed_Maps provides a map with the same operations as the package Containers.Hashed_Maps (see A.18.5), with the difference that the generic formal types Key_Type and Element_Type are indefinite.

Static Semantics

{AI95-00302-03} {AI05-0092-1} The declaration of the generic library package Containers.Indefinite_Hashed_Maps has the same contents and semantics as Containers.Hashed_Maps except:
The generic formal Key_Type is indefinite.
The generic formal Element_Type is indefinite.
The procedure with the profile: 
procedure Insert (Container : in out Map;
                  Key       : in     Key_Type;
                  Position  :    out Cursor;
                  Inserted  :    out Boolean);
is omitted.
Discussion: This procedure is omitted because there is no way to create a default-initialized object of an indefinite type. We considered having this routine insert an empty element similar to the empty elements of a vector, but rejected this possibility because the semantics are fairly complex and very different from the existing case. That would make it more error-prone to convert a container from a definite type to an indefinite type; by omitting the routine completely, any problems will be diagnosed by the compiler.
The actual Element parameter of access subprogram Process of Update_Element may be constrained even if Element_Type is unconstrained. 

Extensions to Ada 95

{AI95-00302-03} The generic package Containers.Indefinite_Hashed_Maps is new. 

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