411 REFERENCE · Wikibooks
Ada Programming/Attributes/'Old
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Description
The value of X on entry, has same type as X.
Each X'Old in a postcondition expression that is enabled, other than those that occur in subexpressions that are determined to be unevaluated, denotes a constant that is implicitly declared at the beginning of the subprogram body, entry body, or accept statement.
Example
X’Old return T