6057 Non-constant expression
Cause
This error occurs if a non-constant expression is used to initialize a constant (for example, an expression involving a property of the current class).
The expression used to initialize a constant must yield a constant value; that is, it must be made up of literal values or other constants (or both).
Action
Change the expression so that it refers only to literal values or to other constants, or both literal values and other constants.