Ada Programming/Attributes/'Succ

Ada. Time-tested, safe and secure.
Ada. Time-tested, safe and secure.

Description edit

X'Succ(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 greater than the input parameter.

The returned discrete value type is the base type of discrete type. If the input parameter is the Last value of the discrete type, then a CONSTRAINT_ERROR exception will be raised.

Example edit

type My_Enum is (Enum1, Enum2, Enum3);
pragma Assert (My_Enum'Succ(Enum2) = Enum3);   -- OK
pragma Assert (My_Enum'Succ(Enum3) = Enum1);   -- Wrong

See also edit

Wikibook edit

Ada Reference Manual edit