Compiler Error C2622

union 'union' : member 'identifier' has assignment operator

The specified union member was declared with an assignment operator, operator=().

A union member is not allowed to have an assignment operator.

The following is an example of this error:

class A
{
   A& operator= ( const A& );  // A's assignment operator
};
union U
{
   A a;                        // error
};