Initializers and Unions

Objects of union type are initialized with a single value (if the union does not have a constructor). This is done in one of two ways:

• Initialize the union with another object of the same union type. For example:

  struct Point
  {
      unsigned x;
      unsigned y;
  };
  union PtLong
  {
      long  l;
      Point pt;
  };
  
  ...
  
  PtLong ptOrigin;
  PtLong ptCurrent = ptOrigin;
  

  In the preceding code, ptCurrent is initialized with the value of ptOrigin — an object of the same type.

• Initialize the union with a brace-enclosed initializer for the first member. For example:

  PtLong ptCurrent = { 0x0a000aL };