A.18.12 The Generic Package Containers.Indefinite_Doubly_Linked_Lists
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{
AI95-00302-03}
The language-defined generic package Containers.Indefinite_Doubly_Linked_Lists
provides private types List and Cursor, and a set of operations for each
type. It provides the same operations as the package Containers.Doubly_Linked_Lists
(see A.18.3), with the difference that the
generic formal Element_Type is indefinite. Static Semantics
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{
AI95-00302-03}
{
AI05-0092-1}
The declaration of the generic library package
Containers.Indefinite_Doubly_Linked_Lists has the
same contents and semantics as
Containers.Doubly_Linked_Lists except:3/2
The generic formal Element_Type
is indefinite.
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The
procedure with the profile:
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procedure Insert (Container : in out List;
Before : in Cursor;
Position : out Cursor;
Count : in Count_Type := 1);
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is omitted.
6.a/2
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 definite container. 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.
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The actual Element parameter
of access subprogram Process of Update_Element may be constrained even
if Element_Type is unconstrained.
Extensions to Ada 95
7.a/2
{
AI95-00302-03}
The generic package Containers.Indefinite_Doubly_Linked_Lists
is new.
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
