Ada Programming/Attributes/'Pos
Description
'Pos is a discrete type attribute. The attribute represents the integer position number of the value passed in as an input parameter. Position numbering starts at 0.
Note that representation clauses do not effect position numbering. Whatever underlying value the enumerated value has, the position number will remain the same.
Example
type My_Enum is (Enum1, Enum2, Enum3); for My_Enum use (Enum1 => 2, Enum2 => 4, Enum3 => 6); ... pragma Assert (My_Enum'Pos(Enum1) = 2); -- Wrong pragma Assert (My_Enum'Pos(Enum1) = 0); -- Right