apaki/cmake_demo
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多态实现的好奇怪，也勉强能用

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46
README.md
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@ -1,39 +1,15 @@
# cmake_demo # cmake_demo
#### 介绍 ## CMAKE
{**以下是 Gitee 平台说明，您可以替换此简介**
Gitee 是 OSCHINA 推出的基于 Git 的代码托管平台（同时支持 SVN）。专为开发者提供稳定、高效、安全的云端软件开发协作平台
无论是个人、团队、或是企业，都能够用 Gitee 实现代码托管、项目管理、协作开发。企业项目请看 [https://gitee.com/enterprises](https://gitee.com/enterprises)}
#### 软件架构 ## 多态
软件架构说明 ### 多态的本质
同样的接口，可以即实现父类的功能，也可以实现子类的功能。主要看传参的类型。
C语言实现思路：
#### 安装教程 因为语法不支持，因此采用特殊的方式来实现。
| 类型 | 实现方式 | 弊端| 问题举例|
1. xxxx | --- | --- | --- | --- |
2. xxxx | 匿名结构体 | 指针 | 多重继承，成员可能冲突 | B->A, C->A, D->B,D->C|
3. xxxx | 虚函数表 | 指针 | 子类父类必须将虚表放在结构体最开头，且不支持多继承下的多态 | |
| 虚函数多参数 | 指针 | 继承的父类无顺序强制要求，且可以多继承。但类方法参数变多 | |
#### 使用说明
1. xxxx
2. xxxx
3. xxxx
#### 参与贡献
1. Fork 本仓库
2. 新建 Feat_xxx 分支
3. 提交代码
4. 新建 Pull Request
#### 特技
1. 使用 Readme\_XXX.md 来支持不同的语言，例如 Readme\_en.md, Readme\_zh.md
2. Gitee 官方博客 [blog.gitee.com](https://blog.gitee.com)
3. 你可以 [https://gitee.com/explore](https://gitee.com/explore) 这个地址来了解 Gitee 上的优秀开源项目
4. [GVP](https://gitee.com/gvp) 全称是 Gitee 最有价值开源项目，是综合评定出的优秀开源项目
5. Gitee 官方提供的使用手册 [https://gitee.com/help](https://gitee.com/help)
6. Gitee 封面人物是一档用来展示 Gitee 会员风采的栏目 [https://gitee.com/gitee-stars/](https://gitee.com/gitee-stars/)

140
main.c
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@ -13,16 +13,16 @@
struct _virtual_table struct _virtual_table
{ {
VIRTUAL void (*area)(void *self); VIRTUAL void (*area)(void *self, void *parent);
VIRTUAL void (*draw)(void *self); VIRTUAL void (*draw)(void *self, void *parent);
}; };
void virtual_area(void *self) void virtual_area(void *self, void *parent)
{ {
ASSERT_CALL_VIRTUAL_METHOD(); ASSERT_CALL_VIRTUAL_METHOD();
} }
void virtual_draw(void *self) void virtual_draw(void *self, void *parent)
{ {
ASSERT_CALL_VIRTUAL_METHOD(); ASSERT_CALL_VIRTUAL_METHOD();
} }
@ -44,24 +44,24 @@ struct _shape
struct _virtual_table vtb; struct _virtual_table vtb;
}; };
void shape_area(void *self) void shape_area(void *self, void *parent)
{ {
struct _shape *pthis = (struct _shape *)self; struct _shape *pthis = (struct _shape *)parent;
pthis->vtb.area(self); pthis->vtb.area(self, NULL);
} }
void shape_draw(void *self) void shape_draw(void *self, void *parent)
{ {
struct _shape *pthis = (struct _shape *)self; struct _shape *pthis = (struct _shape *)parent;
pthis->vtb.draw(self); pthis->vtb.draw(self, NULL);
} }
PRIVATE void _shape_area(void *self) PRIVATE void _shape_area(void *self, void *parent)
{ {
ASSERT_CALL_VIRTUAL_METHOD(); ASSERT_CALL_VIRTUAL_METHOD();
} }
PRIVATE void _shape_draw(void *self) PRIVATE void _shape_draw(void *self, void *parent)
{ {
ASSERT_CALL_VIRTUAL_METHOD(); ASSERT_CALL_VIRTUAL_METHOD();
} }
@ -74,8 +74,8 @@ struct _shape *shape_new(void)
return NULL; return NULL;
} }
static struct _virtual_table vtb = { static struct _virtual_table vtb = {
.area = (void (*)(void *self))_shape_area, .area = (void (*)(void *self, void *parent))_shape_area,
.draw = (void (*)(void *self))_shape_draw .draw = (void (*)(void *self, void *parent))_shape_draw
}; };
shape->vtb = vtb; shape->vtb = vtb;
return shape; return shape;
@ -93,9 +93,12 @@ void shape_free(struct _shape * self)
struct _rect struct _rect
{ {
int invalid;
// super // super
// struct _shape shape; struct _shape shape;
struct _virtual_table vtb; // struct _shape;
// struct _virtual_table vtb;
// attribute // attribute
double width, height; double width, height;
@ -105,12 +108,12 @@ struct _rect
// void (*draw)(void *self); // void (*draw)(void *self);
}; };
void rect_area(struct _rect *self) void rect_area(struct _rect *self, void *parent)
{ {
printf("rect area = %0.2f\n", self->width * self->height); printf("rect area = %0.2f\n", self->width * self->height);
} }
void rect_draw(struct _rect *self) void rect_draw(struct _rect *self, void *parent)
{ {
printf("rect draw\n"); printf("rect draw\n");
} }
@ -126,19 +129,23 @@ struct _rect *rect_new(double width, double height)
rect->height = height; rect->height = height;
static struct _virtual_table vtb = { static struct _virtual_table vtb = {
.area = (void (*)(void *self))rect_area, .area = (void (*)(void *self, void *parent))rect_area,
.draw = (void (*)(void *self))rect_draw .draw = (void (*)(void *self, void *parent))rect_draw
}; };
rect->vtb = vtb; rect->shape.vtb = vtb;
// rect->vtb = vtb;
return rect; return rect;
} }
struct _circle struct _circle
{ {
int invalid;
// super // super
// struct _shape shape; struct _shape shape;
struct _virtual_table vtb; // struct _shape;
// struct _virtual_table vtb;
// attribute // attribute
double radius; double radius;
@ -148,11 +155,11 @@ struct _circle
// void (*draw)(void *self); // void (*draw)(void *self);
}; };
void circle_area(struct _circle *self) void circle_area(struct _circle *self, void *parent)
{ {
printf("circle area = %0.2f\n", 3.14 * self->radius * self->radius); printf("circle area = %0.2f\n", 3.14 * self->radius * self->radius);
} }
void circle_draw(struct _circle *self) void circle_draw(struct _circle *self, void *parent)
{ {
printf("circle draw\n"); printf("circle draw\n");
} }
@ -167,46 +174,85 @@ struct _circle *circle_new(double radius)
circle->radius = radius; circle->radius = radius;
static struct _virtual_table vtb = { static struct _virtual_table vtb = {
.area = (void (*)(void *self))circle_area, .area = (void (*)(void *self, void *parent))circle_area,
.draw = (void (*)(void *self))circle_draw, .draw = (void (*)(void *self, void *parent))circle_draw,
}; };
circle->vtb = vtb; // circle->vtb = vtb;
circle->shape.vtb = vtb;
return circle; return circle;
} }
#if 0
struct _cube
{
// 继承自 struct _shape
struct _rect;
// attibute
double length;
};
void cube_area(struct _cube *self)
{
printf("cube area = %0.2f\n", self->length * self->length * self->length);
}
void cube_draw(struct _cube *self)
{
printf("cube draw\n");
}
struct _cube* cube_new(double length)
{
struct _cube *cube = calloc(1, sizeof(struct _cube));
if (cube == NULL)
{
return NULL;
}
cube->length = length;
static struct _virtual_table vtb = {
.area = (void (*)(void *self))cube_area,
.draw = (void (*)(void *self))cube_draw,
};
cube->vtb = vtb;
return cube;
}
#endif
int main(int argc, char *argv[]) int main(int argc, char *argv[])
{ {
struct _rect *rect = rect_new(4, 5); struct _rect *rect = rect_new(4, 5);
rect_area(rect); rect_area(rect, rect);
rect_draw(rect); rect_draw(rect, rect);
struct _circle *circle = circle_new(3); struct _circle *circle = circle_new(3);
circle_area(circle); circle_area(circle, circle);
circle_draw(circle); circle_draw(circle, circle);
printf("------------------------------\n"); printf("------------------------------\n");
shape_area(rect); shape_area(rect, &rect->shape);
shape_area(circle); shape_draw(rect, &rect->shape);
shape_draw(rect); shape_area(circle, &circle->shape);
shape_draw(circle); shape_draw(circle, &circle->shape);
printf("------------------------------\n"); printf("------------------------------\n");
struct _shape *shape = (struct _shape *)rect_new(2,3); struct _rect *rect2 = (struct _rect *)rect_new(2, 3);
shape_area(shape); shape_area(rect2, &rect2->shape);
shape_draw(shape); shape_draw(rect2, &rect2->shape);
struct _shape *shape2 = NULL;
shape2 = (struct _shape *)circle;
shape_area(shape2);
shape_draw(shape2);
struct _circle *circle2 = (struct _circle *)circle_new(1);
shape_area(circle2, &circle->shape);
shape_draw(circle2, &circle->shape);
printf("------------------------------\n"); printf("------------------------------\n");
struct _shape *shape3 = shape_new(); struct _shape *shape = shape_new();
shape_area(shape3); shape_area(shape, shape);
shape_draw(shape3); shape_draw(shape, shape);
return 0; return 0;
} }