Re: How to model unknown values in a vector?

[Jeffrey Carter <spam@spam.com>]

Harald Schmidt wrote:
 >
 > Does anyone know how to model values in a vector, which are unknown.
 > I can't use the zero value because this is a valid value. Minus
 > infinity could be an option, but I am searching for a better method
 > to handle unknown values.

Use this type for the vector elements:

type Vector_Element (Value_Known : Boolean := False) is record
    case Value_Known is
    when False =>
       null;
    when True =>
       Value : Real_Vector_Element_Type [:= Some_Useful_Default_Value];
    end case;
end record;

-- 
Jeff Carter
"When Roman engineers built a bridge, they had to stand under it
while the first legion marched across. If programmers today
worked under similar ground rules, they might well find
themselves getting much more interested in Ada!"
Robert Dewar