感觉得学习一下优秀的代码框架了。我尝试了很多，但现在想不到好的办法了。

CMakelists.txt

@@ -1,69 +1,14 @@
 
-# 0. cmake 最低版本号要求
 cmake_minimum_required(VERSION 3.8)
-
-# 0. 项目信息
 project(demo)
 
-# 2. 添加当前路径
-set(CMAKE_INCLUDE_CURRENT_DIR ON)
-
-# 2. 配置项目
-option(USE_DEMO "use demo application interface" ON)
-set(VERSION "1.0")
-
-# 2. 配置文件
-configure_file(
-    "${PROJECT_SOURCE_DIR}/config.h.in"
-    "${PROJECT_BINARY_DIR}/config.h"
-)
-
-# 2. 配置条件
-if(USE_DEMO)
-    # include_directories(.)
-# else()
-    # pass
-endif(USE_DEMO)
-
-# 0. 查找当前目录下的所有文件，并将名称保存在DIR_SRC中
-aux_source_directory(. DIR_SRC)
-
-# 1. 添加子目录
-add_subdirectory(src)
-
-# 1. 添加头文件路径
-include_directories(src)
-
-# 0. 指定生成目标
-add_executable(demo  ${DIR_SRC})
-
-# 1. 添加链接库
-# 1.A  如果是动态库，修改了安装路径之后，exe就找不到了怎么破？
-# link_directories(${PROJECT_SOURCE_DIR}/lib)
-# target_link_libraries(demo list_d)
-# 1.B 静态库
-target_link_libraries(demo list)
-
-# 3. 配置安装路径
 set(CMAKE_INSTALL_PREFIX "./release")
-install(TARGETS demo DESTINATION bin)
-install (FILES "${PROJECT_BINARY_DIR}/config.h"
-        DESTINATION include)
 
-# 4. 启用测试
-enable_testing()
-# 测试程序是否成功运行
-add_test (NAME test_demo COMMAND demo 1 2 3 5 8)
-
-# 5. 支持GDB
 set(CMAKE_BUILD_TYPE "Debug")
 set(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g -ggdb")
 set(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -O3 -Wall")
 
-# 
-# 构建一个 CPack 安装包，windows还得添加打包工具
-# 
-# include (InstallRequiredSystemLibraries)
-# set (CPACK_RESOURCE_FILE_LICENSE "${CMAKE_CURRENT_SOURCE_DIR}/License.txt")
-# set (CPACK_PACKAGE_VERSION_MAJOR "${VERSION}")
-# include (CPack)
+include_directories(library)
+
+add_subdirectory(library)
+add_subdirectory(src)

README.en.md

@@ -1,36 +0,0 @@
-# cmake_demo
-
-#### Description
-{**When you're done, you can delete the content in this README and update the file with details for others getting started with your repository**}
-
-#### Software Architecture
-Software architecture description
-
-#### Installation
-
-1.  xxxx
-2.  xxxx
-3.  xxxx
-
-#### Instructions
-
-1.  xxxx
-2.  xxxx
-3.  xxxx
-
-#### Contribution
-
-1.  Fork the repository
-2.  Create Feat_xxx branch
-3.  Commit your code
-4.  Create Pull Request
-
-
-#### Gitee Feature
-
-1.  You can use Readme\_XXX.md to support different languages, such as Readme\_en.md, Readme\_zh.md
-2.  Gitee blog [blog.gitee.com](https://blog.gitee.com)
-3.  Explore open source project [https://gitee.com/explore](https://gitee.com/explore)
-4.  The most valuable open source project [GVP](https://gitee.com/gvp)
-5.  The manual of Gitee [https://gitee.com/help](https://gitee.com/help)
-6.  The most popular members  [https://gitee.com/gitee-stars/](https://gitee.com/gitee-stars/)

README.md

@@ -1,39 +1,15 @@
 # cmake_demo
 
-#### 介绍
-{**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)}
+## CMAKE
 
-#### 软件架构
-软件架构说明
+## 多态
+### 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。
 
-
-#### 安装教程
-
-1.  xxxx
-2.  xxxx
-3.  xxxx
-
-#### 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/)
+C语言实现思路：
+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| 
+| --- | --- | --- | --- |
+| 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|
+| 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。多继承需要人为注意是调用了其他类还是继承了其他类 | |

config.h.in

@@ -1,2 +0,0 @@
-#cmakedefine USE_DEMO 
-#cmakedefine VERSION "@VERSION@"

library/CMakelists.txt

@@ -0,0 +1,13 @@
+
+project(class)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+# 当前目录下的文件 -> 写入变量
+aux_source_directory(. SRCS)
+
+# 生成链接库
+add_library(${PROJECT_NAME} SHARED ${SRCS})
+
+# 配置安装库
+install (TARGETS ${PROJECT_NAME} DESTINATION bin)

library/circle.c

@@ -0,0 +1,57 @@
+
+#include "circle.h"
+
+double circle_area(void *self, void *parent)
+{
+    double area = 0;
+    struct _circle *pthis = (struct _circle *)parent;
+    area = pthis->shape->vtb.area(self, NULL);
+    return area;
+}
+
+void circle_draw(void *self, void *parent)
+{
+    struct _circle *pthis = (struct _circle *)parent;
+    pthis->shape->vtb.draw(self, NULL);
+}
+
+double _circle_area(void *self, void *parent)
+{
+    struct _circle *pthis = (struct _circle *)self;
+    double area = 3.14 * pthis->radius * pthis->radius;
+    printf("circle area = %0.2f\n", area);
+    return area;
+}
+
+void _circle_draw(void *self,  void *parent)
+{
+    printf("circle draw\n");
+}
+
+struct _circle *circle_new(double radius)
+{
+    // super
+    static struct _virtual_table vtb = {
+        .area = (double (*)(void *self, void *parent))_circle_area,
+        .draw = (void (*)(void *self, void *parent))_circle_draw,
+    };
+
+    struct _shape *shape = shape_new();
+    if (shape == NULL)
+    {
+        return NULL;
+    }
+    shape->vtb = vtb;
+
+    // self
+    struct _circle *circle = calloc(1, sizeof(struct _circle));
+    if (circle == NULL)
+    {
+        return NULL;
+    }
+    circle->radius = radius;
+    // set parent
+    circle->shape = shape;
+
+    return circle;
+}

library/circle.h

@@ -0,0 +1,28 @@
+
+#ifndef _CIRCLE_H_
+#define _CIRCLE_H_
+
+#include "common.h"
+#include "shape.h"
+
+struct _circle
+{
+    int invalid;
+
+    // super
+    struct _shape *shape;
+
+    // attribute
+    double radius;
+
+    // method
+    // void (*area)(void *self);
+    // void (*draw)(void *self);
+};
+
+struct _circle *circle_new(double radius);
+
+double circle_area(void *self, void *parent);
+void circle_draw(void *self, void *parent);
+
+#endif

library/common.h

@@ -0,0 +1,24 @@
+
+#ifndef _COMMON_H_
+#define _COMMON_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <stdarg.h>
+
+// [warring] offsetof is redefined in stddef.h
+// 
+// #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+// #define container_of(ptr, type, member) ({ \
+//     const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+//     (type *)( (char *)__mptr - offsetof(type,member) );})
+
+#define _offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+#define container_of(ptr, type, member) ({ \
+    const typeof( ((type *)0)->member ) *__mptr = (ptr); \
+    (type *)( (char *)__mptr - _offsetof(type,member) );})
+
+#endif

library/copper.c

@@ -0,0 +1,69 @@
+
+#include "copper.h"
+
+double copper_cash_area(struct _copper_cash *self, void *parent)
+{
+    // 如果用的继承，那么就不能直接调用父类的虚接口，实现自己。
+    // 因为父类虚接口，是自己实现的。这样相当于自己调用自己。导致卡死。
+
+    // double circle_area = self->circle->shape->vtb.area(self->circle, self->circle);
+    // double rect_area = self->rect->shape->vtb.area(self->rect, self->rect);
+
+    double circle_area = 3.14 * self->circle->radius * self->circle->radius;
+    double rect_area = self->rect->width * self->rect->height;
+    double area = circle_area - rect_area;
+
+    printf("copper cash area = %0.2f\n", circle_area - rect_area);
+    return area;
+}
+
+void copper_cash_draw(struct _copper_cash *self, void *parent)
+{
+    printf("copper cash draw\n");
+}
+
+
+struct _copper_cash *copper_cash_new(double width, double height, double radius)
+{
+    // super
+    static struct _virtual_table vtb = {
+        .area = (double (*)(void *self, void *parent))copper_cash_area,
+        .draw = (void (*)(void *self, void *parent))copper_cash_draw,
+    };
+
+    struct _shape *shape = shape_new();
+    if (shape == NULL)
+    {
+        return NULL;
+    }
+    shape->vtb = vtb;
+
+    struct _rect *rect = rect_new(width, height);
+    if(rect == NULL)
+    {
+        return NULL;
+    }
+    rect->shape = shape;
+
+    struct _circle *circle = circle_new(radius);
+    if (circle == NULL)
+    {
+        return NULL;
+    }
+    circle->shape = shape;
+
+    // self
+    struct _copper_cash *cc = calloc(1, sizeof(struct _copper_cash));
+    if (cc == NULL)
+    {
+        return NULL;
+    }
+    cc->self = cc;
+
+    cc->price = 100;
+    // set parent
+    cc->shape = shape;
+    cc->rect = rect;
+    cc->circle = circle;
+    return cc;
+}

library/copper.h

@@ -0,0 +1,26 @@
+
+#ifndef _COPPER_CASH_H_
+#define _COPPER_CASH_H_
+
+#include "common.h"
+#include "shape.h"
+#include "rect.h"
+#include "circle.h"
+
+struct _copper_cash
+{
+    struct _copper_cash *self;
+
+    struct _shape *shape;
+    struct _rect *rect;
+    struct _circle *circle;
+
+    double price;
+};
+
+struct _copper_cash *copper_cash_new(double width, double height, double radius);
+
+double copper_cash_area(struct _copper_cash *self, void *parent);
+void copper_cash_draw(struct _copper_cash *self, void *parent);
+
+#endif

library/rect.c

@@ -0,0 +1,61 @@
+
+#include "rect.h"
+
+double rect_area(void *self, void *parent)
+{
+    double area = 0;
+    struct _rect *pthis = (struct _rect *)parent;
+    area = pthis->shape->vtb.area(self, NULL);
+    return area;
+}
+
+void rect_draw(void *self, void *parent)
+{
+    struct _rect *pthis = (struct _rect *)parent;
+    pthis->shape->vtb.draw(self, NULL);
+}
+
+double _rect_area(void *self, void *parent)
+{
+    struct _rect *pthis = (struct _rect *)self;
+    double area = pthis->width * pthis->height;
+
+    printf("rect area = %0.2f\n", area);
+    return area;
+}
+
+void _rect_draw(void *self, void *parent)
+{
+    printf("rect draw\n");
+}
+
+struct _rect *rect_new(double width, double height)
+{
+    // super
+    static struct _virtual_table vtb = {
+        .area = (double (*)(void *self, void *parent))_rect_area,
+        .draw = (void (*)(void *self, void *parent))_rect_draw,
+    };
+
+    struct _shape *shape = shape_new();
+    if (shape == NULL)
+    {
+        return NULL;
+    }
+    shape->vtb = vtb;
+
+    // self
+    struct _rect *rect = calloc(1, sizeof(struct _rect));
+    if (rect == NULL)
+    {
+        return NULL;
+    }
+    rect->self = rect;
+
+    rect->width = width;
+    rect->height = height;
+    // set parent
+    rect->shape = shape;
+
+    return rect;
+}

library/rect.h

@@ -0,0 +1,25 @@
+
+#ifndef _RECT_H_
+#define _RECT_H_
+
+#include "common.h"
+#include "shape.h"
+
+struct _rect
+{
+    // int invalid;
+    struct _rect *self;    
+
+    // super
+    struct _shape *shape;
+
+    // attribute
+    double width, height;
+};
+
+struct _rect *rect_new(double width, double height);
+
+double rect_area(void *self, void *parent);
+void rect_draw(void *self, void *parent);
+
+#endif

library/shape.c

@@ -0,0 +1,77 @@
+
+#include "shape.h"
+
+double virtual_area(void *self, void *parent)
+{
+    ASSERT_CALL_VIRTUAL_METHOD();
+}
+
+void virtual_draw(void *self, void *parent)
+{
+    ASSERT_CALL_VIRTUAL_METHOD();
+}
+
+struct _virtual_table *virtual_new(void)
+{
+    struct _virtual_table *vtb = calloc(1, sizeof(struct _virtual_table));
+    if (vtb == NULL)
+    {
+        return NULL;
+    }
+    vtb->area = virtual_area;
+    vtb->draw = virtual_draw;
+    return vtb;
+}
+
+
+
+double shape_area(void *self, void *parent)
+{
+    double area = 0;
+    struct _shape *pthis = (struct _shape *)parent;
+    area = pthis->vtb.area(self, NULL);
+    return area;
+}
+
+void shape_draw(void *self, void *parent)
+{
+    struct _shape *pthis = (struct _shape *)parent;
+    pthis->vtb.draw(self, NULL);
+}
+
+PRIVATE double _shape_area(void *self, void *parent)
+{
+    ASSERT_CALL_VIRTUAL_METHOD();
+}
+
+PRIVATE void _shape_draw(void *self, void *parent)
+{
+    ASSERT_CALL_VIRTUAL_METHOD();
+}
+
+struct _shape *shape_new(void)
+{
+    struct _shape *shape = calloc(1, sizeof(struct _shape));
+    if(shape == NULL)
+    {
+        return NULL;
+    }
+    shape->self = shape;
+
+    static struct _virtual_table vtb = {
+        .area = (double (*)(void *self, void *parent))_shape_area, 
+        .draw = (void (*)(void *self, void *parent))_shape_draw
+    };
+    shape->vtb = vtb;
+    return shape;
+}
+
+#if 0
+void shape_free(struct _shape * self)
+{
+    if (self != NULL)
+    {
+        free(self);
+    }
+}
+#endif

library/shape.h

@@ -0,0 +1,32 @@
+
+#ifndef _SHAPE_H_
+#define _SHAPE_H_
+
+#include "common.h"
+
+#define VIRTUAL  
+#define PRIVATE static 
+
+#define ASSERT_CALL_VIRTUAL_METHOD() assert(!("can't call abstract method"))
+
+struct _virtual_table
+{
+    VIRTUAL double (*area)(void *self, void *parent);
+    VIRTUAL void (*draw)(void *self, void *parent);
+};
+
+struct _shape
+{
+    struct _shape *self;
+    
+    struct _virtual_table vtb;
+};
+
+
+struct _shape *shape_new(void);
+
+double shape_area(void *self, void *parent);
+void shape_draw(void *self, void *parent);
+
+#endif
+

mk.bat

@@ -1,6 +1,8 @@
 @REM D:\Lang\cmake-3.27.5-windows-x86_64\bin\cmake.EXE --no-warn-unused-cli -DCMAKE_BUILD_TYPE:STRING=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_C_COMPILER:FILEPATH=D:\Software\mingw64\bin\gcc.exe -DCMAKE_CXX_COMPILER:FILEPATH=D:\Software\mingw64\bin\g++.exe -SF:/OpenDemo/1_vsc_cmake -Bf:/OpenDemo/1_vsc_cmake/build -G "MinGW Makefiles"
 @REM cmake -Bbuild -G "Visual Studio 17 2022"
 
+del ".\\build\\release\\bin\\demo.exe"
+
 cmake -B build -G "MinGW Makefiles"
 
 make -C build
@@ -9,3 +11,5 @@ make -C build test
 
 @REM cpack -C ./build/CPackConfig.cmake
 @REM cpack -C ./build/CPackSourceConfig.cmake
+
+".\\build\\release\\bin\\demo.exe"

src/CMakelists.txt

@@ -1,17 +1,14 @@
 
-# 当前目录下的文件 -> 写入变量
-aux_source_directory(. DIR_LIB_SRC)
+project(demo)
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
-# 生成链接库
-# add_library(list ${DIR_LIB_SRC})
-add_library(list STATIC ${DIR_LIB_SRC})
-add_library(list_d SHARED ${DIR_LIB_SRC})
+aux_source_directory(. SRCS)
 
-# 配置安装头文件
-install (FILES list.h DESTINATION include)
-# 配置安装库
-install (TARGETS list DESTINATION bin)
+add_executable(${PROJECT_NAME}  ${SRCS})
 
-# install (TARGETS list_d DESTINATION bin)
-# install (TARGETS list_d DESTINATION lib)
+target_link_libraries(
+    ${PROJECT_NAME}
+    class
+)
 
+install(TARGETS ${PROJECT_NAME} DESTINATION bin)

src/list.c

@@ -1,58 +0,0 @@
-
-#include "list.h"
-
-void list_init(struct list_t *list)
-{
-    list->data = 0;
-    list->next = NULL;
-}
-
-void list_add(struct list_t *list, uint8_t data)
-{
-    struct list_t *p = NULL;
-    p = list;
-    while (p->next != NULL)
-    {
-        p = p->next;
-        if (p->data == data)
-        {
-            return;
-        }
-    }
-    p->next = (struct list_t *)malloc(sizeof(struct list_t));
-    p->next->data = data;
-    p->next->next = NULL;
-    return;
-}
-
-void list_print(struct list_t *list)
-{
-    struct list_t *p = NULL;
-    p = list;
-    while (p->next != NULL)
-    {
-        printf("%02d ", p->data);
-        p = p->next;
-        if (p->next == NULL)
-        {
-            printf("%02d\n", p->data);
-            break;
-        }
-    }
-}
-
-void list_free(struct list_t *list)
-{
-    struct list_t *p = NULL;
-    p = list;
-    while (p->next != NULL)
-    {
-        p = p->next;
-        free(p->next);
-        p->next = NULL;
-        if (p->next == NULL)
-        {
-            break;
-        }
-    }
-}

src/list.h

@@ -1,20 +0,0 @@
-
-#ifndef _LIST_H_
-#define _LIST_H_
-
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-typedef struct list_t
-{
-    uint8_t  data;
-    struct list_t *next;
-} list_t;
-
-void list_init(struct list_t *list);
-void list_add(struct list_t *list, uint8_t data);
-void list_print(struct list_t *list);
-void list_free(struct list_t *list);
-
-#endif

src/main.c

@@ -0,0 +1,51 @@
+
+#include "shape.h"
+#include "rect.h"
+#include "circle.h"
+#include "copper.h"
+
+int main(int argc, char *argv[])
+{
+    struct _rect *rect = rect_new(4, 5);
+    rect_area(rect, rect);
+    rect_draw(rect, rect);
+
+    struct _circle *circle = circle_new(3);
+    circle_area(circle, circle);
+    circle_draw(circle, circle);
+
+    printf("----- rect & circle -----\n");
+    shape_area(rect, rect->shape);
+    shape_draw(rect, rect->shape);
+
+    shape_area(circle, circle->shape);
+    shape_draw(circle, circle->shape);
+
+    printf("----- [2] rect & circle -----\n");
+    struct _rect *rect2 = (struct _rect *)rect_new(2, 3);
+    shape_area(rect2, rect2->shape);
+    shape_draw(rect2, rect2->shape);
+
+    struct _circle *circle2 = (struct _circle *)circle_new(1);
+    shape_area(circle2, circle->shape);
+    shape_draw(circle2, circle->shape);
+
+    // printf("----- [2] shape -----\n");
+    // struct _shape *shape = shape_new();
+    // shape_area(shape, shape);
+    // shape_draw(shape, shape);
+
+    printf("----- copper_cash -----\n");
+    struct _copper_cash *cc = copper_cash_new(2, 2, 4);
+    shape_area(cc, cc->shape);
+    shape_draw(cc, cc->shape);
+
+    printf("----- [2] copper_cash -----\n");
+    rect_area(cc, cc->rect);
+    rect_draw(cc, cc->rect);
+
+    circle_area(cc, cc->circle);
+    circle_draw(cc, cc->circle);
+
+    return 0;
+}