| 
            Last change
 on this file since 656c8ac was             520fa9e, checked in by Peter A. Buhr <pabuhr@…>, 12 months ago           | 
        
        
          | 
             
proofread background chapter, and other small changes 
 
           | 
        
        
          
            
              - 
Property                 mode
 set to                 
100644
               
             
           | 
        
        
          | 
            File size:
            1.4 KB
           | 
        
      
      
| Line |   | 
|---|
| 1 | #include <stdio.h>
 | 
|---|
| 2 | #include <assert.h>
 | 
|---|
| 3 | #include <stdlib.h>
 | 
|---|
| 4 | 
 | 
|---|
| 5 | #define SHOW(x, fmt) printf( #x ": " fmt "\n", x )
 | 
|---|
| 6 | 
 | 
|---|
| 7 | #ifdef ERRS
 | 
|---|
| 8 | #define ERR(...) __VA_ARGS__
 | 
|---|
| 9 | #else
 | 
|---|
| 10 | #define ERR(...)
 | 
|---|
| 11 | #endif
 | 
|---|
| 12 | 
 | 
|---|
| 13 | 
 | 
|---|
| 14 | 
 | 
|---|
| 15 | int main() {
 | 
|---|
| 16 |         float ar[3][10];
 | 
|---|
| 17 |         static_assert( sizeof(float) == 4 );    $\C{// floats (atomic elements) are 4 bytes}$
 | 
|---|
| 18 |         static_assert( sizeof(void*) == 8 );    $\C{// pointers are 8 bytes}$
 | 
|---|
| 19 | 
 | 
|---|
| 20 |         static_assert( sizeof(ar) == 120 );             $\C{// the array, float[3][10]}$
 | 
|---|
| 21 |         static_assert( sizeof(ar[0]) == 40 );   $\C{// its first element, float[10]}$
 | 
|---|
| 22 |         static_assert( sizeof(ar[0][0]) == 4 ); $\C{// its first grand element, float}$
 | 
|---|
| 23 | 
 | 
|---|
| 24 |         static_assert( sizeof(&(ar)) == 8 );    $\C{// pointer to the array, float(*)[3][10]}$
 | 
|---|
| 25 |         static_assert( sizeof(&(ar[0])) == 8 ); $\C{// pointer to its first element, float(*)[10]}$
 | 
|---|
| 26 |         static_assert( sizeof(&(ar[0][0])) == 8 );      $\C{// pointer to its first grand-element, float*}$
 | 
|---|
| 27 | 
 | 
|---|
| 28 |         float (*pa)[3][10] = &(ar);
 | 
|---|
| 29 |         float (*pa0)[10] = &(ar[0]);
 | 
|---|
| 30 |         float *pa00 = &(ar[0][0]);
 | 
|---|
| 31 | 
 | 
|---|
| 32 |         static_assert( (void*)&ar == (void*)&(ar[0] ) );
 | 
|---|
| 33 |         static_assert( (void*)&ar == (void*)&(ar[0][0]) );
 | 
|---|
| 34 | 
 | 
|---|
| 35 |         assert( (void *) pa == (void *) pa0 );
 | 
|---|
| 36 |         assert( (void *) pa == (void *) pa00 );
 | 
|---|
| 37 | 
 | 
|---|
| 38 | //      float (*b[3])[10];
 | 
|---|
| 39 |         float *b[3];
 | 
|---|
| 40 |         for (int i = 0; i < 3; i ++) {
 | 
|---|
| 41 |                 b[i] = malloc(sizeof(float[10]));
 | 
|---|
| 42 |         }
 | 
|---|
| 43 |         ar[2][3];
 | 
|---|
| 44 |         b[2][3];
 | 
|---|
| 45 | /*
 | 
|---|
| 46 | 
 | 
|---|
| 47 | */
 | 
|---|
| 48 | 
 | 
|---|
| 49 | }
 | 
|---|
| 50 | 
 | 
|---|
| 51 | // Local Variables: //
 | 
|---|
| 52 | // compile-command: "sed -f sedcmd bkgd-carray-mdim.c | gcc-11 -Wall -Wextra -x c -" //
 | 
|---|
| 53 | // End: //
 | 
|---|
       
      
  Note:
 See   
TracBrowser
 for help on using the repository browser.