Free Pascal supports the set types as in Turbo Pascal. The prototype of a set declaration is:
SetType = Set of TargetType;
Each of the elements of SetType must be of type TargetType. TargetType can be any ordinal type with a range between 0 and 255. A set can contain maximally 255 elements.
The following is a valid set declaration:
Type Days = (Mon, Tue, Wed, Thu, Fri, Sqt, Sun); Var WeekDays : Set of days;Given this set declaration, the follwing assignment is legal:
WeekDays := [ Mon, Tue, Wed, Thu, Fri];The operators for manipulations of sets are listed in table (1.4).
| Operation | Operator |
| Union | + |
| Difference | - |
| Intersection | * |
You can compare two sets with the <> and = operators, but not (yet) with the < and > operators.
As of compiler version 0.9.5, the compiler stores small sets (less than 32 elements) in a longint, if the type range allows it. This allows for faster processing and decreases program size. Otherwise, sets are stored in 32 bytes.