==== tests/cases/conformance/expressions/assignmentOperator/compoundAdditionAssignmentWithInvalidOperands.ts (27 errors) ====
    enum E { a, b }
    
    var a: void;
    
    var x1: boolean;
    x1 += a;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types 'boolean' and 'void'.
    x1 += true;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'boolean' and 'boolean'.
    x1 += 0;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types 'boolean' and 'number'.
    x1 += E.a;
    ~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'boolean' and 'E'.
    x1 += {};
    ~~~~~~~~
!!! Operator '+=' cannot be applied to types 'boolean' and '{}'.
    x1 += null;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'boolean' and 'boolean'.
    x1 += undefined;
    ~~~~~~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'boolean' and 'boolean'.
    
    var x2: {};
    x2 += a;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types '{}' and 'void'.
    x2 += true;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types '{}' and 'boolean'.
    x2 += 0;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types '{}' and 'number'.
    x2 += E.a;
    ~~~~~~~~~
!!! Operator '+=' cannot be applied to types '{}' and 'E'.
    x2 += {};
    ~~~~~~~~
!!! Operator '+=' cannot be applied to types '{}' and '{}'.
    x2 += null;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types '{}' and '{}'.
    x2 += undefined;
    ~~~~~~~~~~~~~~~
!!! Operator '+=' cannot be applied to types '{}' and '{}'.
    
    var x3: void;
    x3 += a;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types 'void' and 'void'.
    x3 += true;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'void' and 'boolean'.
    x3 += 0;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types 'void' and 'number'.
    x3 += E.a;
    ~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'void' and 'E'.
    x3 += {};
    ~~~~~~~~
!!! Operator '+=' cannot be applied to types 'void' and '{}'.
    x3 += null;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'void' and 'void'.
    x3 += undefined;
    ~~~~~~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'void' and 'void'.
    
    var x4: number;
    x4 += a;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types 'number' and 'void'.
    x4 += true;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'number' and 'boolean'.
    x4 += {};
    ~~~~~~~~
!!! Operator '+=' cannot be applied to types 'number' and '{}'.
    
    var x5: E;
    x5 += a;
    ~~~~~~~
!!! Operator '+=' cannot be applied to types 'E' and 'void'.
    x5 += true;
    ~~~~~~~~~~
!!! Operator '+=' cannot be applied to types 'E' and 'boolean'.
    x5 += {};
    ~~~~~~~~
!!! Operator '+=' cannot be applied to types 'E' and '{}'.