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 A.18.24 The Generic Package Containers.Bounded_Ordered_Sets

{AI05-0001-1} The language-defined generic package Containers.Bounded_Ordered_Sets provides a private type Set and a set of operations. It provides the same operations as the package Containers.Ordered_Sets (see A.18.9), with the difference that the maximum storage is bounded.

Static Semantics

{AI05-0001-1} The declaration of the generic library package Containers.Bounded_Ordered_Sets has the same contents and semantics as Containers.Ordered_Sets except:
The pragma Preelaborate is replaced with pragma Pure.
The type Set is declared with a discriminant that specifies the capacity (maximum number of elements) as follows: 
  type Set (Capacity : Count_Type) is tagged private;
The type Set needs finalization if and only if type Element_Type needs finalization.
Implementation Note: {AI05-0212-1} The type Set cannot depend on package Ada.Finalization unless the element type depends on that package. The objects returned from the Iterator and Reference functions probably do depend on package Ada.Finalization. Restricted environments may need to avoid use of those functions and their associated types. 
If Insert (or Include) adds an element, a check is made that the capacity is not exceeded, and Capacity_Error is raised if this check fails.
In procedure Assign, if Source length is greater than Target capacity, then Capacity_Error is propagated.
The function Copy is replaced with: 
  function Copy (Source : Set;
                 Capacity : Count_Type := 0) return Set;
Returns a set whose elements are initialized from the values in Source. If Capacity is 0, then the set capacity is the length of Source; if Capacity is equal to or greater than the length of Source, the set capacity is the specified value; otherwise, the operation propagates Capacity_Error. 

Bounded (Run-Time) Errors

 {AI05-0160-1} {AI05-0265-1} It is a bounded error to use a bounded set if it was the target of an assignment_statement whose source was in the middle of an operation that prohibits tampering with elements [or cursors]. Either Program_Error is raised, or the operation proceeds as defined. 

Implementation Requirements

 {AI05-0184-1} {AI05-0264-1} For each instance of Containers.Ordered_Sets and each instance of Containers.Bounded_Ordered_Sets, if the two instances meet the following conditions, then the output generated by the Set'Output or Set'Write subprograms of either instance shall be readable by the Set'Input or Set'Read of the other instance, respectively:
{AI05-0184-1} {AI05-0248-1} the Element_Type parameters of the two instances are statically matching subtypes of the same type; and
{AI05-0184-1} the output generated by Element_Type'Output or Element_Type'Write is readable by Element_Type'Input or Element_Type'Read, respectively (where Element_Type denotes the type of the two actual Element_Type parameters). 

Implementation Advice

 {AI05-0001-1} Bounded set objects should be implemented without implicit pointers or dynamic allocation. 
 {AI05-0001-1} The implementation advice for procedure Move to minimize copying does not apply. 

Extensions to Ada 2005

{AI05-0001-1} {AI05-0160-1} {AI05-0184-1} The generic package Containers.Bounded_Ordered_Sets is new. 

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