Compiler Error C2675
Visual Studio 2012
unary 'operator' : 'type' does not define this operator or a conversion to a type acceptable to the predefined operator
C2675 can also occur when using a unary operator, and the type does not define the operator or a conversion to a type acceptable to the predefined operator. To use the operator, you must overload it for the specified type or define a conversion to a type for which the operator is defined.