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Ada Programming/Attributes/'Pred
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Attributes 'Pred
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Description
X'Pred(Y) is an Ada attribute where X is any discrete type and Y is a value of that type. This attribute represents the discrete value that has a position number of one less than the input parameter.
The returned discrete value type is the base type of discrete type. If the input parameter is the First value of the discrete type, then a CONSTRAINT_ERROR exception will be raised.
Example
type My_Enum is (Enum1, Enum2, Enum3);
...
Assert (My_Enum'Pred (Enum2) = Enum1); OK
Assert (My_Enum'Pred (Enum1) = Enum3); Wrong
See also
Wikibook
Ada Programming
Ada Programming/Attributes/'Succ
Ada Reference Manual
13 3 Operational and Representation Attributes
K Language-Defined Attributes
Pred