==== tests/cases/conformance/expressions/binaryOperators/inOperator/inOperatorWithInvalidOperands.ts (20 errors) ====
    enum E { a }
    
    var x: any;
    
    // invalid left operands
    // the left operand is required to be of type Any, the String primitive type, or the Number primitive type
    var a1: boolean;
    var a2: void;
    var a3: {};
    var a4: E
    
    var ra1 = a1 in x;
              ~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra2 = a2 in x;
              ~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra3 = a3 in x;
              ~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra4 = a4 in x;
              ~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra5 = null in x;
              ~~~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra6 = undefined in x;
              ~~~~~~~~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra7 = E.a in x;
              ~~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra8 = false in x;
              ~~~~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    var ra9 = {} in x;
              ~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
    
    // invalid right operands
    // the right operand is required to be of type Any, an object type, or a type parameter type
    var b1: number;
    var b2: boolean;
    var b3: string;
    var b4: void;
    
    var rb1 = x in b1;
                   ~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb2 = x in b2;
                   ~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb3 = x in b3;
                   ~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb4 = x in b4;
                   ~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb5 = x in 0;
                   ~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb6 = x in false;
                   ~~~~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb7 = x in '';
                   ~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb8 = x in null;
                   ~~~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    var rb9 = x in undefined;
                   ~~~~~~~~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter
    
    // both operands are invalid
    var rc1 = {} in '';
              ~~
!!! The left-hand side of an 'in' expression must be of types 'any', 'string' or 'number'.
                    ~~
!!! The right-hand side of an 'in' expression must be of type 'any', an object type or a type parameter