source: doc/theses/mike_brooks_MMath/programs/bkgd-carray-mdim.c@ 4205c07

Last change on this file since 4205c07 was b195498, checked in by Peter A. Buhr <pabuhr@…>, 5 months ago

proofreading intro and background chapters, capitalize section titles, update backtick calls to regular calls

  • 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
15int main() {
16 float mx[3][10];
17 static_assert( sizeof(float) == 4 ); $\C[3.25in]{// floats (atomic elements) are 4 bytes}$
18 static_assert( sizeof(void *) == 8 ); $\C{// pointers are 8 bytes}$
19
20 static_assert( sizeof(mx) == 120 ); $\C{// the array, float[3][10]}$
21 static_assert( sizeof(mx[0]) == 40 ); $\C{// its first element, float[10]}$
22 static_assert( sizeof(mx[0][0]) == 4 ); $\C{// its first grand element, float}$
23
24 static_assert( sizeof(&(mx)) == 8 ); $\C{// pointer to the array, float(*)[3][10]}$
25 static_assert( sizeof(&(mx[0])) == 8 ); $\C{// pointer to its first element, float(*)[10]}$
26 static_assert( sizeof(&(mx[0][0])) == 8 ); $\C{// pointer to its first grand-element, float*}\CRT$
27
28 float (*pm)[3][10] = &(mx);
29 float (*pm0)[10] = &(mx[0]);
30 float *pm00 = &(mx[0][0]);
31
32 static_assert( (void *)&mx == (void *)&(mx[0] ) );
33 static_assert( (void *)&mx == (void *)&(mx[0][0]) );
34
35 assert( (void *) pm == (void *) pm0 );
36 assert( (void *) pm == (void *) pm00 );
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 mx[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: //
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