1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
// This examples demonstrates the basic usage of Interface99.
#include <interface99.h>
#include <stdio.h>
// clang-format off
#define Shape_IFACE \
vfunc( int, perim, const VSelf) \
vfunc(void, scale, VSelf, int factor)
// clang-format on
interface(Shape);
// Rectangle implementation
// ============================================================
typedef struct {
int a, b;
} Rectangle;
int Rectangle_perim(const VSelf) {
VSELF(const Rectangle);
return (self->a + self->b) * 2;
}
void Rectangle_scale(VSelf, int factor) {
VSELF(Rectangle);
self->a *= factor;
self->b *= factor;
}
impl(Shape, Rectangle);
// Triangle implementation
// ============================================================
typedef struct {
int a, b, c;
} Triangle;
int Triangle_perim(const VSelf) {
VSELF(const Triangle);
return self->a + self->b + self->c;
}
void Triangle_scale(VSelf, int factor) {
VSELF(Triangle);
self->a *= factor;
self->b *= factor;
self->c *= factor;
}
impl(Shape, Triangle);
// Test
// ============================================================
void test(Shape shape) {
printf("perim = %d\n", VCALL(shape, perim));
VCALL(shape, scale, 5);
printf("perim = %d\n", VCALL(shape, perim));
}
/*
* Output:
* perim = 24
* perim = 120
* perim = 60
* perim = 300
*/
int main(void) {
Shape r = DYN_LIT(Rectangle, Shape, {5, 7});
Shape t = DYN_LIT(Triangle, Shape, {10, 20, 30});
test(r);
test(t);
return 0;
}
|
