castError.cfa:7:1 error: Cannot choose between 3 alternatives for expression Cast of: Name: f ... to: char Alternatives are: Cost ( 1, 0, 0, 0 ): Cast of: Variable Expression: f: function accepting unspecified arguments ... returning nothing ... to: char (types: char ) Environment: Cost ( 1, 0, 0, 0 ): Cast of: Variable Expression: f: double ... to: char (types: char ) Environment: Cost ( 1, 0, 0, 0 ): Cast of: Variable Expression: f: signed int ... to: char (types: char ) Environment: