1 // struct definition and declaration
2 struct a {
3 int a;
4 int b;
5 } c;
6
7 // Useless, but legal struct declaration
8 struct {
9 int x;
10 };
11
12 // Useful anonymous struct declaration
13 struct {
14 int y;
15 } anon1, anon2;
16
17 // forward declarations
18 struct a;
19 struct b;
20 struct c;
21
22 struct b {int a; int b; };
23
24 // struct c {b g; }; // syntax error.
25
26 // struct s {float c,a,b,c;} s; // duplicate struct member
27
28 struct c {struct b g; };
29
30 // struct a { int w; }; // error
31
testCopying()32 void testCopying() {
33 struct a {int a[10]; char c;} a, b;
34 a.c = 37;
35 b.c = 38;
36 b = a;
37 printf("testCopying: %d == %d\n", a.c, b.c);
38 }
39
testUnion()40 void testUnion() {
41 union u;
42 union u {float f;int i;} u;
43 u.f = 1.0f;
44 printf("testUnion: %g == 0x%08x\n", u.f, u.i);
45 }
46
47 struct v {float x, y, z, w; };
48
add(struct v * result,struct v * a,struct v * b)49 void add(struct v* result, struct v* a, struct v* b) {
50 result->x = a->x + b->x;
51 result->y = a->y + b->y;
52 result->z = a->z + b->z;
53 result->w = a->w + b->w;
54 }
55
set(struct v * v,float x,float y,float z,float w)56 void set(struct v* v, float x, float y, float z, float w) {
57 v->x = x;
58 v->y = y;
59 v->z = z;
60 v->w = w;
61 }
62
print(struct v * v)63 void print(struct v* v) {
64 printf("(%g, %g, %g, %g)\n", v->x, v->y, v->z, v->w);
65 }
66
testArgs()67 void testArgs() {
68 struct v a, b, c;
69 set(&a, 1.0f, 2.0f, 3.0f, 4.0f);
70 set(&b, 5.0f, 6.0f, 7.0f, 8.0f);
71 add(&c, &a, &b);
72 printf("testArgs: ");
73 print(&c);
74 }
75
main()76 int main() {
77 anon1.y = 3;
78 anon2.y = anon1.y;
79
80 testCopying();
81 testUnion();
82 testArgs();
83
84 struct c cc;
85 cc.g.a = 3;
86 c.a = 1;
87 c.b = 3;
88 struct a {int x, y; } z;
89 // struct a {int x, y; } z2;
90 z.x = c.a;
91 struct a *pA;
92 pA = &z;
93 pA->x += 5;
94 return pA->x;
95 }
96