13.10 Unchecked Access Value Creation

From OC Systems Wiki!
< Guide:95lrm
Revision as of 23:35, 4 May 2019 by imported>WikiVisor (1 revision imported)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

The attribute Unchecked_Access is used to create access values in an unsafe manner -- the programmer is responsible for preventing dangling references.

Static Semantics

The following attribute is defined for a prefix X that denotes an aliased view of an object:

X'Unchecked_Access
All rules and semantics that apply to X'Access (see 3.10.2) apply also to X'Unchecked_Access, except that, for the purposes of accessibility rules and checks, it is as if X were declared immediately within a library package.

Notes

21  This attribute is provided to support the situation where a local object is to be inserted into a global linked data structure, when the programmer knows that it will always be removed from the data structure prior to exiting the object's scope. The Access attribute would be illegal in this case (see 3.10.2, Operations of Access Types).

22  There is no Unchecked_Access attribute for subprograms.

Copyright © 1992,1993,1994,1995 Intermetrics, Inc.
Copyright © 2000 The MITRE Corporation, Inc. Ada Reference Manual