c++ - Why do I need a reinterpret_cast to convert Fred ** const to void ** const? -


I have a constant pointer for an indicator at Fred and I do not understand Is that static_cast is not enough 

  type -phil {int n; } Fred; Fred * PFed; Fred ** Concepfread = & amp; PFD; Void ** const pivoide = static_cast & lt; Void ** const & gt; (Pffread);   
 Anyone can explain that an  reinterpret_cast  to change an indicator to  fred *  in  void * Why is the need to convert pointer to  fread  on  void   but  static_cast  is fine.   
 
 
 There is no requirement that a  fread *  and  zero *  has the same size and representation. (I have worked on machines where they were not, although it was before my C ++ days.) When you change  from Fred *  to  void *  So you get a new pointer, possibly with a different shape and representation, but there is no information about the size and representation of the object  zero *  indicates that you know it is unknown, and The only way to use this  zero *  is to call it  Fread *  (modulo things like CD-qualifiers) is inserted into it. When you change  from Fred **  to  zero ** , you can see a solid type (a  Fred * ) from an indicator Indicator for solid type (an indicator for a  zero * ) And because there is no guarantee that these two solid types have the same size and representation, a  reinterpret_cast  is required for the conversion  zero  a special, non-concrete type So that you can do  static_cast  on any type and by an indicator  zero .  Zero *  is just another solid indicator type, so ranging from pointers to general rules (and requires  reinterpret_cast ).  
 In many ways, the situation is like  int  and  double , where  zero *   int  plays (say), and  Fred *  is the role of  double . There is no problem between  int  and  double   static_cast  ing, but  int *  and  double * 
 needed  reinterpret_cast .

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