c - Access structure members without using '.' or '->' operator -

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this question has answer here:

how access keyvalue , alternatekeyvalue dell laptop definition without using '.' or '->' operators directly reference qwerty struct or members.

i tried looking solution didn't find any. please me find way access it?

typedef enum {     mouse_none,     mouse_up,     mouse_down,     mouse_left,     mouse_right, } mouse_direction_e;  typedef struct {     bool leftbutton;     bool rightbutton;     bool middlebutton;     bool mouseon;     mouse_direction_e direction; } mouse_s;  typedef struct {     char keyvalue;     char alternatekeyvalue; } keyboard_s;  typedef struct {     mouse_s simplemouse;     keyboard_s qwerty; } laptop_s;  laptop_s dell = {     .simplemouse =     {         .leftbutton = false,         .rightbutton = false,         .middlebutton = false,         .mouseon = false,         .direction = mouse_none,     },     .qwerty =     {         .keyvalue = '5',         .alternatekeyvalue = '%'     }, };

this sounds homework question....

howzabout this:

int index = 0; bool leftmousebutton = *( (bool *) &( ( (char*) &dell )[0]) ); /*                                              \ 1 /   *                                       \  2 /  *                                                     \3/   *                                 \___________ 4 _________/  *                        \_ 5 _/  *                     \_________________ 6 _________________/  */ bool rightmousebutton = *( (bool *) &( ( (char*) &dell )[ sizeof(bool) - 1 ]) ); /* etc.  enjoy math! */

in words:

for struct element located x bytes deep dell

  1. get address of dell
  2. cast address ptr array of bytes (chars) -- or if of struct content same size int, cast address int* (remember adjust subsequent math accordingly!)
  3. determine offset of desired element start of struct dell.
  4. get address desired element.
  5. cast address ptr of same type element we're presently working with.
  6. get data @ address of element we're presently working with. in other words: value of element.

tell me how did on assignment!


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