A.18.1 The Package Containers
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The package Containers is the root of the containers subsystem.
Static Semantics
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The library package Containers has the following declaration:
package Ada.Containers
is
pragma Pure(Containers);
type Hash_Type
is mod implementation-defined;
type Count_Type
is range 0 ..
implementation-defined;
end Ada.Containers;
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Hash_Type represents the range of the result of a hash function. Count_Type
represents the (potential or actual) number of elements of a container.
Implementation defined: The value of
Containers.Hash_Type'Modulus. The value of Containers.Count_Type'Last.
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Capacity_Error is raised when the capacity of a container is exceeded.
Implementation Advice
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Hash_Type'Modulus should be at least 2**32. Count_Type'Last should be
at least 2**31–1.
Implementation Advice: Containers.Hash_Type'Modulus
should be at least 2**32. Containers.Count_Type'Last should be at least
2**31–1.
Discussion: This is not a requirement
so that these types can be declared properly on machines with native
sizes that are not 32 bits. For instance, a 24-bit target could use 2**24
for Hash_Type'Modulus.
Extensions to Ada 95
Incompatibilities With Ada 2005
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Exception Capacity_Error is added to Containers.
If Containers is referenced in a
use_clause,
and an entity with the name Capacity_Error is defined in a package that
is also referenced in a
use_clause,
the entity Capacity_Error may no longer be use-visible, resulting in
errors. This should be rare and is easily fixed if it does occur.
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe
